diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/DaprAspNetCore/AbpDaprEndpointRouteBuilderExtensions.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/DaprAspNetCore/AbpDaprEndpointRouteBuilderExtensions.cs
index b5866c5a68..24f68ef9ab 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/DaprAspNetCore/AbpDaprEndpointRouteBuilderExtensions.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/DaprAspNetCore/AbpDaprEndpointRouteBuilderExtensions.cs
@@ -30,7 +30,7 @@ namespace Dapr
         /// <summary>
         /// An optional delegate used to configure the subscriptions.
         /// </summary>
-        public Func<List<AbpSubscription>, Task> SubscriptionsCallback { get; set; }
+        public Func<List<AbpSubscription>, Task>? SubscriptionsCallback { get; set; }
     }
 
     /// <summary>
@@ -41,32 +41,32 @@ namespace Dapr
         /// <summary>
         /// Gets or sets the topic name.
         /// </summary>
-        public string Topic { get; set; }
+        public string Topic { get; set; } = default!;
 
         /// <summary>
         /// Gets or sets the pubsub name
         /// </summary>
-        public string PubsubName { get; set; }
+        public string PubsubName { get; set; } = default!;
 
         /// <summary>
         /// Gets or sets the route
         /// </summary>
-        public string Route { get; set; }
+        public string? Route { get; set; }
 
         /// <summary>
         /// Gets or sets the routes
         /// </summary>
-        public AbpRoutes Routes { get; set; }
+        public AbpRoutes? Routes { get; set; }
 
         /// <summary>
         /// Gets or sets the metadata.
         /// </summary>
-        public AbpMetadata Metadata { get; set; }
+        public AbpMetadata? Metadata { get; set; }
 
         /// <summary>
         /// Gets or sets the deadletter topic.
         /// </summary>
-        public string DeadLetterTopic { get; set; }
+        public string? DeadLetterTopic { get; set; }
     }
 
     /// <summary>
@@ -99,12 +99,12 @@ namespace Dapr
         /// <summary>
         /// Gets or sets the default route
         /// </summary>
-        public string Default { get; set; }
+        public string? Default { get; set; }
 
         /// <summary>
         /// Gets or sets the routing rules
         /// </summary>
-        public List<AbpRule> Rules { get; set; }
+        public List<AbpRule>? Rules { get; set; }
     }
 
     /// <summary>
@@ -115,12 +115,12 @@ namespace Dapr
         /// <summary>
         /// Gets or sets the CEL expression to match this route.
         /// </summary>
-        public string Match { get; set; }
+        public string Match { get; set; } = default!;
 
         /// <summary>
         /// Gets or sets the path of the route.
         /// </summary>
-        public string Path { get; set; }
+        public string Path { get; set; } = default!;
     }
 }
 
@@ -166,7 +166,7 @@ namespace Microsoft.AspNetCore.Builder
             return CreateSubscribeEndPoint(endpoints, options);
         }
 
-        private static IEndpointConventionBuilder CreateSubscribeEndPoint(IEndpointRouteBuilder endpoints, AbpSubscribeOptions options = null)
+        private static IEndpointConventionBuilder CreateSubscribeEndPoint(IEndpointRouteBuilder endpoints, AbpSubscribeOptions? options = null)
         {
             if (endpoints is null)
             {
@@ -175,7 +175,7 @@ namespace Microsoft.AspNetCore.Builder
 
             return endpoints.MapGet("dapr/subscribe", async context =>
             {
-                var logger = context.RequestServices.GetRequiredService<ILoggerFactory>().CreateLogger("DaprTopicSubscription");
+                var logger = context.RequestServices.GetService<ILoggerFactory>()?.CreateLogger("DaprTopicSubscription");
                 var dataSource = context.RequestServices.GetRequiredService<EndpointDataSource>();
                 var subscriptions = dataSource.Endpoints
                     .OfType<RouteEndpoint>()
@@ -185,7 +185,7 @@ namespace Microsoft.AspNetCore.Builder
                         var topicMetadata = e.Metadata.GetOrderedMetadata<ITopicMetadata>();
                         var originalTopicMetadata = e.Metadata.GetOrderedMetadata<IOriginalTopicMetadata>();
 
-                        var subs = new List<(string PubsubName, string Name, string DeadLetterTopic, bool? EnableRawPayload, string Match, int Priority, Dictionary<string, string[]> OriginalTopicMetadata, string MetadataSeparator, RoutePattern RoutePattern)>();
+                        var subs = new List<(string PubsubName, string Name, string? DeadLetterTopic, bool? EnableRawPayload, string Match, int Priority, Dictionary<string, string[]> OriginalTopicMetadata, string? MetadataSeparator, RoutePattern RoutePattern)>();
 
                         for (int i = 0; i < topicMetadata.Count(); i++)
                         {
@@ -211,7 +211,7 @@ namespace Microsoft.AspNetCore.Builder
                     {
                         var first = e.First();
                         var rawPayload = e.Any(e => e.EnableRawPayload.GetValueOrDefault());
-                        var metadataSeparator = e.FirstOrDefault(e => !string.IsNullOrEmpty(e.MetadataSeparator)).MetadataSeparator ?? ",";
+                        var metadataSeparator = e.FirstOrDefault(e => !string.IsNullOrEmpty(e.MetadataSeparator)).MetadataSeparator?.ToString() ?? ",";
                         var rules = e.Where(e => !string.IsNullOrEmpty(e.Match)).ToList();
                         var defaultRoutes = e.Where(e => string.IsNullOrEmpty(e.Match)).Select(e => RoutePatternToString(e.RoutePattern)).ToList();
                         var defaultRoute = defaultRoutes.FirstOrDefault();
@@ -276,7 +276,7 @@ namespace Microsoft.AspNetCore.Builder
                     .OrderBy(e => (e.PubsubName, e.Topic))
                     .ToList();
 
-                await options?.SubscriptionsCallback(subscriptions);
+                await options?.SubscriptionsCallback!(subscriptions)!;
                 await context.Response.WriteAsync(JsonSerializer.Serialize(subscriptions,
                     new JsonSerializerOptions
                     {
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus.csproj b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus.csproj
index f31ded0e06..96b196b67f 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus.csproj
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFramework>net7.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <RootNamespace />
     </PropertyGroup>
 
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo/Abp/AspNetCore/Mvc/Dapr/EventBus/Controllers/AbpAspNetCoreMvcDaprEventsController.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo/Abp/AspNetCore/Mvc/Dapr/EventBus/Controllers/AbpAspNetCoreMvcDaprEventsController.cs
index b1d5bac7fb..946c39f59c 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo/Abp/AspNetCore/Mvc/Dapr/EventBus/Controllers/AbpAspNetCoreMvcDaprEventsController.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr.EventBus/Volo/Abp/AspNetCore/Mvc/Dapr/EventBus/Controllers/AbpAspNetCoreMvcDaprEventsController.cs
@@ -41,8 +41,8 @@ public class AbpAspNetCoreMvcDaprEventsController : AbpController
         }
         else
         {
-            var eventData = daprSerializer.Deserialize(data, distributedEventBus.GetEventType(topic));
-            await distributedEventBus.TriggerHandlersAsync(distributedEventBus.GetEventType(topic), eventData);
+            var eventData = daprSerializer.Deserialize(data, distributedEventBus.GetEventType(topic!));
+            await distributedEventBus.TriggerHandlersAsync(distributedEventBus.GetEventType(topic!), eventData);
         }
 
         return Ok();
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo.Abp.AspNetCore.Mvc.Dapr.csproj b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo.Abp.AspNetCore.Mvc.Dapr.csproj
index 03bb453ba2..1839113d06 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo.Abp.AspNetCore.Mvc.Dapr.csproj
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo.Abp.AspNetCore.Mvc.Dapr.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFramework>net7.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <RootNamespace />
     </PropertyGroup>
 
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprAppApiTokenValidator.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprAppApiTokenValidator.cs
index dd0c6a5300..aa7d17072b 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprAppApiTokenValidator.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprAppApiTokenValidator.cs
@@ -50,9 +50,9 @@ public class DaprAppApiTokenValidator : IDaprAppApiTokenValidator, ISingletonDep
         return expectedAppApiToken == headerAppApiToken;
     }
 
-    public virtual string GetDaprAppApiTokenOrNull()
+    public virtual string? GetDaprAppApiTokenOrNull()
     {
-        string apiTokenHeader = HttpContext.Request.Headers["dapr-api-token"];
+        string? apiTokenHeader = HttpContext.Request.Headers["dapr-api-token"];
         if (string.IsNullOrEmpty(apiTokenHeader) || apiTokenHeader.Length < 1)
         {
             return null;
@@ -61,7 +61,7 @@ public class DaprAppApiTokenValidator : IDaprAppApiTokenValidator, ISingletonDep
         return apiTokenHeader;
     }
 
-    protected virtual string GetConfiguredAppApiTokenOrNull()
+    protected virtual string? GetConfiguredAppApiTokenOrNull()
     {
         return HttpContext
             .RequestServices
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprHttpContextExtensions.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprHttpContextExtensions.cs
index aa81765b12..e73eaec4f7 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprHttpContextExtensions.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/DaprHttpContextExtensions.cs
@@ -22,7 +22,7 @@ public static class DaprHttpContextExtensions
             .IsValidDaprAppApiToken();
     }
 
-    public static string GetDaprAppApiTokenOrNull(HttpContext httpContext)
+    public static string? GetDaprAppApiTokenOrNull(HttpContext httpContext)
     {
         return httpContext
             .RequestServices
diff --git a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/IDaprAppApiTokenValidator.cs b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/IDaprAppApiTokenValidator.cs
index 66fd833b77..f54f0aa8cf 100644
--- a/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/IDaprAppApiTokenValidator.cs
+++ b/framework/src/Volo.Abp.AspNetCore.Mvc.Dapr/Volo/Abp/AspNetCore/Mvc/Dapr/IDaprAppApiTokenValidator.cs
@@ -6,5 +6,5 @@ public interface IDaprAppApiTokenValidator
 
     bool IsValidDaprAppApiToken();
 
-    string GetDaprAppApiTokenOrNull();
+    string? GetDaprAppApiTokenOrNull();
 }
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo.Abp.Imaging.Abstractions.csproj b/framework/src/Volo.Abp.Imaging.Abstractions/Volo.Abp.Imaging.Abstractions.csproj
index 6b7c0434ed..288f43c7d4 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo.Abp.Imaging.Abstractions.csproj
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo.Abp.Imaging.Abstractions.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <PackageId>Volo.Abp.Imaging.Abstractions</PackageId>
         <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
         <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressor.cs b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressor.cs
index 949a3fb848..6d80cd1c6b 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressor.cs
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressor.cs
@@ -9,13 +9,13 @@ public interface IImageCompressor
 {
     Task<ImageCompressResult<Stream>> CompressAsync(
         Stream stream,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default
     );
 
     Task<ImageCompressResult<byte[]>> CompressAsync(
         byte[] bytes,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default
     );
 }
\ No newline at end of file
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressorContributor.cs b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressorContributor.cs
index 84087d983a..7fc9362c77 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressorContributor.cs
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageCompressorContributor.cs
@@ -9,10 +9,10 @@ public interface IImageCompressorContributor
 {
     Task<ImageCompressResult<Stream>> TryCompressAsync(
         Stream stream, 
-        [CanBeNull] string mimeType = null, 
+        string? mimeType = null, 
         CancellationToken cancellationToken = default);
     Task<ImageCompressResult<byte[]>> TryCompressAsync(
         byte[] bytes, 
-        [CanBeNull] string mimeType = null, 
+        string? mimeType = null, 
         CancellationToken cancellationToken = default);
 }
\ No newline at end of file
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizer.cs b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizer.cs
index c2ae1b62e9..2c9c2878ed 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizer.cs
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizer.cs
@@ -10,14 +10,14 @@ public interface IImageResizer
     Task<ImageResizeResult<Stream>> ResizeAsync(
         Stream stream,
         ImageResizeArgs resizeArgs,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default
     );
 
     Task<ImageResizeResult<byte[]>> ResizeAsync(
         byte[] bytes,
         ImageResizeArgs resizeArgs,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default
     );
 }
\ No newline at end of file
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizerContributor.cs b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizerContributor.cs
index fed4ce4a4c..a6603ea136 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizerContributor.cs
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/IImageResizerContributor.cs
@@ -10,12 +10,12 @@ public interface IImageResizerContributor
     Task<ImageResizeResult<Stream>> TryResizeAsync(
         Stream stream, 
         ImageResizeArgs resizeArgs, 
-        [CanBeNull] string mimeType = null, 
+        string? mimeType = null, 
         CancellationToken cancellationToken = default);
     
     Task<ImageResizeResult<byte[]>> TryResizeAsync(
         byte[] bytes, 
         ImageResizeArgs resizeArgs, 
-        [CanBeNull] string mimeType = null, 
+        string? mimeType = null, 
         CancellationToken cancellationToken = default);
 }
\ No newline at end of file
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageCompressor.cs b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageCompressor.cs
index 11789776c7..d36a9d6ea0 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageCompressor.cs
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageCompressor.cs
@@ -23,7 +23,7 @@ public class ImageCompressor : IImageCompressor, ITransientDependency
 
     public virtual async Task<ImageCompressResult<Stream>> CompressAsync(
         [NotNull] Stream stream,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         Check.NotNull(stream, nameof(stream));
@@ -45,7 +45,7 @@ public class ImageCompressor : IImageCompressor, ITransientDependency
 
     public virtual async Task<ImageCompressResult<byte[]>> CompressAsync(
         [NotNull] byte[] bytes,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         Check.NotNull(bytes, nameof(bytes));
diff --git a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageResizer.cs b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageResizer.cs
index 139fc194dd..e2c4ad7d77 100644
--- a/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageResizer.cs
+++ b/framework/src/Volo.Abp.Imaging.Abstractions/Volo/Abp/Imaging/ImageResizer.cs
@@ -31,7 +31,7 @@ public class ImageResizer : IImageResizer, ITransientDependency
     public virtual async Task<ImageResizeResult<Stream>> ResizeAsync(
         [NotNull] Stream stream, 
         ImageResizeArgs resizeArgs, 
-        [CanBeNull] string mimeType = null, 
+        string? mimeType = null, 
         CancellationToken cancellationToken = default)
     {
         Check.NotNull(stream, nameof(stream));
@@ -56,7 +56,7 @@ public class ImageResizer : IImageResizer, ITransientDependency
     public virtual async Task<ImageResizeResult<byte[]>> ResizeAsync(
         [NotNull] byte[] bytes, 
         ImageResizeArgs resizeArgs, 
-        [CanBeNull] string mimeType = null, 
+        string? mimeType = null, 
         CancellationToken cancellationToken = default)
     {
         Check.NotNull(bytes, nameof(bytes));
diff --git a/framework/src/Volo.Abp.Imaging.AspNetCore/Volo.Abp.Imaging.AspNetCore.csproj b/framework/src/Volo.Abp.Imaging.AspNetCore/Volo.Abp.Imaging.AspNetCore.csproj
index d727d99a7c..8b8810e000 100644
--- a/framework/src/Volo.Abp.Imaging.AspNetCore/Volo.Abp.Imaging.AspNetCore.csproj
+++ b/framework/src/Volo.Abp.Imaging.AspNetCore/Volo.Abp.Imaging.AspNetCore.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFramework>net7.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <PackageId>Volo.Abp.Imaging.AspNetCore</PackageId>
         <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
         <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
diff --git a/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/CompressImageAttribute.cs b/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/CompressImageAttribute.cs
index 1ddd8822be..e49a5abc9f 100644
--- a/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/CompressImageAttribute.cs
+++ b/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/CompressImageAttribute.cs
@@ -28,7 +28,7 @@ public class CompressImageAttribute : ActionFilterAttribute
 
         foreach (var (key, value) in parameters)
         {
-            object compressedValue = value switch {
+            object? compressedValue = value switch {
                 IFormFile file => await CompressImageAsync(file, imageCompressor),
                 IRemoteStreamContent remoteStreamContent => await CompressImageAsync(remoteStreamContent, imageCompressor),
                 Stream stream => await CompressImageAsync(stream, imageCompressor),
diff --git a/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/ResizeImageAttribute.cs b/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/ResizeImageAttribute.cs
index 799cd81877..65b59bef6f 100644
--- a/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/ResizeImageAttribute.cs
+++ b/framework/src/Volo.Abp.Imaging.AspNetCore/Volo/Abp/Imaging/ResizeImageAttribute.cs
@@ -41,7 +41,7 @@ public class ResizeImageAttribute : ActionFilterAttribute
         
         foreach (var (key, value) in parameters)
         {
-            object resizedValue = value switch {
+            object? resizedValue = value switch {
                 IFormFile file => await ResizeImageAsync(file, imageResizer),
                 IRemoteStreamContent remoteStreamContent => await ResizeImageAsync(remoteStreamContent, imageResizer),
                 Stream stream => await ResizeImageAsync(stream, imageResizer),
diff --git a/framework/src/Volo.Abp.Imaging.ImageSharp/Volo.Abp.Imaging.ImageSharp.csproj b/framework/src/Volo.Abp.Imaging.ImageSharp/Volo.Abp.Imaging.ImageSharp.csproj
index d523a292ba..29d6a3944e 100644
--- a/framework/src/Volo.Abp.Imaging.ImageSharp/Volo.Abp.Imaging.ImageSharp.csproj
+++ b/framework/src/Volo.Abp.Imaging.ImageSharp/Volo.Abp.Imaging.ImageSharp.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <PackageId>Volo.Abp.Imaging.ImageSharp</PackageId>
         <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
         <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
diff --git a/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageCompressorContributor.cs b/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageCompressorContributor.cs
index a54d006b30..8d2f29dd02 100644
--- a/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageCompressorContributor.cs
+++ b/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageCompressorContributor.cs
@@ -26,7 +26,7 @@ public class ImageSharpImageCompressorContributor : IImageCompressorContributor,
 
     public virtual async Task<ImageCompressResult<Stream>> TryCompressAsync(
         Stream stream, 
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(mimeType) && !CanCompress(mimeType))
@@ -54,7 +54,7 @@ public class ImageSharpImageCompressorContributor : IImageCompressorContributor,
 
     public virtual async Task<ImageCompressResult<byte[]>> TryCompressAsync(
         byte[] bytes, 
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(mimeType) && !CanCompress(mimeType))
@@ -75,7 +75,7 @@ public class ImageSharpImageCompressorContributor : IImageCompressorContributor,
         return new ImageCompressResult<byte[]>(newBytes, result.State);
     }
 
-    protected virtual bool CanCompress(string mimeType)
+    protected virtual bool CanCompress(string? mimeType)
     {
         return mimeType switch {
             MimeTypes.Image.Jpeg => true,
diff --git a/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageResizerContributor.cs b/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageResizerContributor.cs
index d2ac92eaf7..92dbc25034 100644
--- a/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageResizerContributor.cs
+++ b/framework/src/Volo.Abp.Imaging.ImageSharp/Volo/Abp/Imaging/ImageSharpImageResizerContributor.cs
@@ -16,7 +16,7 @@ public class ImageSharpImageResizerContributor : IImageResizerContributor, ITran
     public virtual async Task<ImageResizeResult<Stream>> TryResizeAsync(
         Stream stream,
         ImageResizeArgs resizeArgs,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(mimeType) && !CanResize(mimeType))
@@ -58,7 +58,7 @@ public class ImageSharpImageResizerContributor : IImageResizerContributor, ITran
     public virtual async Task<ImageResizeResult<byte[]>> TryResizeAsync(
         byte[] bytes, 
         ImageResizeArgs resizeArgs,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(mimeType) && !CanResize(mimeType))
@@ -82,7 +82,7 @@ public class ImageSharpImageResizerContributor : IImageResizerContributor, ITran
         return new ImageResizeResult<byte[]>(newBytes, result.State);
     }
 
-    protected virtual bool CanResize(string mimeType)
+    protected virtual bool CanResize(string? mimeType)
     {
         return mimeType switch {
             MimeTypes.Image.Jpeg => true,
diff --git a/framework/src/Volo.Abp.Imaging.MagickNet/Volo.Abp.Imaging.MagickNet.csproj b/framework/src/Volo.Abp.Imaging.MagickNet/Volo.Abp.Imaging.MagickNet.csproj
index 535f689663..0e3581908a 100644
--- a/framework/src/Volo.Abp.Imaging.MagickNet/Volo.Abp.Imaging.MagickNet.csproj
+++ b/framework/src/Volo.Abp.Imaging.MagickNet/Volo.Abp.Imaging.MagickNet.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <PackageId>Volo.Abp.Imaging.MagicNet</PackageId>
         <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
         <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
diff --git a/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageCompressorContributor.cs b/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageCompressorContributor.cs
index a0900cd14a..3aba7f5000 100644
--- a/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageCompressorContributor.cs
+++ b/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageCompressorContributor.cs
@@ -28,7 +28,7 @@ public class MagickImageCompressorContributor : IImageCompressorContributor, ITr
 
     public virtual async Task<ImageCompressResult<Stream>> TryCompressAsync(
         Stream stream, 
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(mimeType) && !CanCompress(mimeType))
@@ -63,7 +63,7 @@ public class MagickImageCompressorContributor : IImageCompressorContributor, ITr
 
     public virtual async Task<ImageCompressResult<byte[]>> TryCompressAsync(
         byte[] bytes, 
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(mimeType) && !CanCompress(mimeType))
@@ -86,7 +86,7 @@ public class MagickImageCompressorContributor : IImageCompressorContributor, ITr
         return new ImageCompressResult<byte[]>(newBytes, result.State);
     }
     
-    protected virtual bool CanCompress(string mimeType)
+    protected virtual bool CanCompress(string? mimeType)
     {
         return mimeType switch {
             MimeTypes.Image.Jpeg => true,
diff --git a/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageResizerContributor.cs b/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageResizerContributor.cs
index 9ffb6133e5..b71230e8bb 100644
--- a/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageResizerContributor.cs
+++ b/framework/src/Volo.Abp.Imaging.MagickNet/Volo/Abp/Imaging/MagickImageResizerContributor.cs
@@ -16,7 +16,7 @@ public class MagickImageResizerContributor : IImageResizerContributor, ITransien
     public virtual async Task<ImageResizeResult<Stream>> TryResizeAsync(
         Stream stream,
         ImageResizeArgs resizeArgs,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!mimeType.IsNullOrWhiteSpace() && !CanResize(mimeType))
@@ -54,7 +54,7 @@ public class MagickImageResizerContributor : IImageResizerContributor, ITransien
     public virtual Task<ImageResizeResult<byte[]>> TryResizeAsync(
         byte[] bytes,
         ImageResizeArgs resizeArgs,
-        [CanBeNull] string mimeType = null,
+        string? mimeType = null,
         CancellationToken cancellationToken = default)
     {
         if (!mimeType.IsNullOrWhiteSpace() && !CanResize(mimeType))
@@ -74,7 +74,7 @@ public class MagickImageResizerContributor : IImageResizerContributor, ITransien
         return Task.FromResult(new ImageResizeResult<byte[]>(image.ToByteArray(), ImageProcessState.Done));
     }
 
-    protected virtual bool CanResize(string mimeType)
+    protected virtual bool CanResize(string? mimeType)
     {
         return mimeType switch {
             MimeTypes.Image.Jpeg => true,
diff --git a/framework/src/Volo.Abp.Json/Volo.Abp.Json.csproj b/framework/src/Volo.Abp.Json/Volo.Abp.Json.csproj
index 40049addba..67dfaf2a28 100644
--- a/framework/src/Volo.Abp.Json/Volo.Abp.Json.csproj
+++ b/framework/src/Volo.Abp.Json/Volo.Abp.Json.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.Json</AssemblyName>
     <PackageId>Volo.Abp.Json</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo.Abp.TextTemplating.Core.csproj b/framework/src/Volo.Abp.TextTemplating.Core/Volo.Abp.TextTemplating.Core.csproj
index 8581d01dc4..f405dfe00c 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo.Abp.TextTemplating.Core.csproj
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo.Abp.TextTemplating.Core.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <RootNamespace />
     </PropertyGroup>
 
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTemplateRenderer.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTemplateRenderer.cs
index 43cc829010..6e17d6701a 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTemplateRenderer.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTemplateRenderer.cs
@@ -25,9 +25,9 @@ public class AbpTemplateRenderer : ITemplateRenderer, ITransientDependency
 
     public virtual async Task<string> RenderAsync(
         string templateName,
-        object model = null,
-        string cultureName = null,
-        Dictionary<string, object> globalContext = null)
+        object? model = null,
+        string? cultureName = null,
+        Dictionary<string, object>? globalContext = null)
     {
         var templateDefinition = await TemplateDefinitionManager.GetAsync(templateName);
 
@@ -38,7 +38,7 @@ public class AbpTemplateRenderer : ITemplateRenderer, ITransientDependency
             renderEngine = Options.DefaultRenderingEngine;
         }
 
-        var providerType = Options.RenderingEngines.GetOrDefault(renderEngine);
+        var providerType = Options.RenderingEngines.GetOrDefault(renderEngine!);
 
         if (providerType != null && typeof(ITemplateRenderingEngine).IsAssignableFrom(providerType))
         {
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTextTemplatingOptions.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTextTemplatingOptions.cs
index 28b2e28ad0..40dac35703 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTextTemplatingOptions.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/AbpTextTemplatingOptions.cs
@@ -10,7 +10,7 @@ public class AbpTextTemplatingOptions
     public ITypeList<ITemplateContentContributor> ContentContributors { get; }
     public IDictionary<string, Type> RenderingEngines { get; }
 
-    public string DefaultRenderingEngine { get; set; }
+    public string? DefaultRenderingEngine { get; set; }
 
     public HashSet<string> DeletedTemplates { get; }
 
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IDynamicTemplateDefinitionStore.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IDynamicTemplateDefinitionStore.cs
index e275eb39be..205cae5824 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IDynamicTemplateDefinitionStore.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IDynamicTemplateDefinitionStore.cs
@@ -10,5 +10,5 @@ public interface IDynamicTemplateDefinitionStore
 
     Task<IReadOnlyList<TemplateDefinition>> GetAllAsync();
 
-    Task<TemplateDefinition> GetOrNullAsync(string name);
+    Task<TemplateDefinition?> GetOrNullAsync(string name);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IStaticTemplateDefinitionStore.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IStaticTemplateDefinitionStore.cs
index d298a42541..6e6d763616 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IStaticTemplateDefinitionStore.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/IStaticTemplateDefinitionStore.cs
@@ -10,5 +10,5 @@ public interface IStaticTemplateDefinitionStore
 
     Task<IReadOnlyList<TemplateDefinition>> GetAllAsync();
 
-    Task<TemplateDefinition> GetOrNullAsync(string name);
+    Task<TemplateDefinition?> GetOrNullAsync(string name);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentContributor.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentContributor.cs
index fadd8696a8..086644db98 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentContributor.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentContributor.cs
@@ -4,5 +4,5 @@ namespace Volo.Abp.TextTemplating;
 
 public interface ITemplateContentContributor
 {
-    Task<string> GetOrNullAsync(TemplateContentContributorContext context);
+    Task<string?> GetOrNullAsync(TemplateContentContributorContext context);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentProvider.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentProvider.cs
index ac944946c0..1fe3f25d5f 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentProvider.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateContentProvider.cs
@@ -5,16 +5,16 @@ namespace Volo.Abp.TextTemplating;
 
 public interface ITemplateContentProvider
 {
-    Task<string> GetContentOrNullAsync(
+    Task<string?> GetContentOrNullAsync(
         [NotNull] string templateName,
-        [CanBeNull] string cultureName = null,
+        string? cultureName = null,
         bool tryDefaults = true,
         bool useCurrentCultureIfCultureNameIsNull = true
     );
 
-    Task<string> GetContentOrNullAsync(
+    Task<string?> GetContentOrNullAsync(
         [NotNull] TemplateDefinition templateDefinition,
-        [CanBeNull] string cultureName = null,
+        string? cultureName = null,
         bool tryDefaults = true,
         bool useCurrentCultureIfCultureNameIsNull = true
     );
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionContext.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionContext.cs
index f2caa3c805..fd219ea23c 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionContext.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionContext.cs
@@ -6,7 +6,7 @@ public interface ITemplateDefinitionContext
 {
     IReadOnlyList<TemplateDefinition> GetAll();
 
-    TemplateDefinition GetOrNull(string name);
+    TemplateDefinition? GetOrNull(string name);
 
     void Add(params TemplateDefinition[] definitions);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionManager.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionManager.cs
index fa20673cea..b8903db522 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionManager.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateDefinitionManager.cs
@@ -12,6 +12,5 @@ public interface ITemplateDefinitionManager
     [ItemNotNull]
     Task<IReadOnlyList<TemplateDefinition>> GetAllAsync();
 
-    [ItemCanBeNull]
-    Task<TemplateDefinition> GetOrNullAsync(string name);
+    Task<TemplateDefinition?> GetOrNullAsync(string name);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderer.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderer.cs
index 62e17f69a8..324984d44b 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderer.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderer.cs
@@ -17,8 +17,8 @@ public interface ITemplateRenderer
     /// <returns></returns>
     Task<string> RenderAsync(
         [NotNull] string templateName,
-        [CanBeNull] object model = null,
-        [CanBeNull] string cultureName = null,
-        [CanBeNull] Dictionary<string, object> globalContext = null
+        object? model = null,
+        string? cultureName = null,
+        Dictionary<string, object>? globalContext = null
     );
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderingEngine.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderingEngine.cs
index da080ffdb3..e100825011 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderingEngine.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/ITemplateRenderingEngine.cs
@@ -19,8 +19,8 @@ public interface ITemplateRenderingEngine
     /// <returns></returns>
     Task<string> RenderAsync(
         [NotNull] string templateName,
-        [CanBeNull] object model = null,
-        [CanBeNull] string cultureName = null,
-        [CanBeNull] Dictionary<string, object> globalContext = null
+        object? model = null,
+        string? cultureName = null,
+        Dictionary<string, object>? globalContext = null
     );
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/NullIDynamicTemplateDefinitionStore.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/NullIDynamicTemplateDefinitionStore.cs
index 115f46b2ac..5c72c6e7c4 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/NullIDynamicTemplateDefinitionStore.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/NullIDynamicTemplateDefinitionStore.cs
@@ -8,13 +8,13 @@ namespace Volo.Abp.TextTemplating;
 
 public class NullIDynamicTemplateDefinitionStore : IDynamicTemplateDefinitionStore, ISingletonDependency
 {
-    private readonly static Task<TemplateDefinition> CachedTemplateResult = Task.FromResult((TemplateDefinition)null);
+    private readonly static Task<TemplateDefinition?> CachedTemplateResult = Task.FromResult((TemplateDefinition?)null);
 
     private readonly static Task<IReadOnlyList<TemplateDefinition>> CachedTemplatesResult = Task.FromResult((IReadOnlyList<TemplateDefinition>)Array.Empty<TemplateDefinition>().ToImmutableList());
 
     public Task<TemplateDefinition> GetAsync(string name)
     {
-        return CachedTemplateResult;
+        return CachedTemplateResult!;
     }
 
     public Task<IReadOnlyList<TemplateDefinition>> GetAllAsync()
@@ -22,7 +22,7 @@ public class NullIDynamicTemplateDefinitionStore : IDynamicTemplateDefinitionSto
         return CachedTemplatesResult;
     }
 
-    public Task<TemplateDefinition> GetOrNullAsync(string name)
+    public Task<TemplateDefinition?> GetOrNullAsync(string name)
     {
         return CachedTemplateResult;
     }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/StaticTemplateDefinitionStore.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/StaticTemplateDefinitionStore.cs
index d12db86da8..4231f39b4d 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/StaticTemplateDefinitionStore.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/StaticTemplateDefinitionStore.cs
@@ -36,7 +36,7 @@ public class StaticTemplateDefinitionStore : IStaticTemplateDefinitionStore, ISi
             throw new AbpException("Undefined template: " + name);
         }
 
-        return template;
+        return template!;
     }
 
     public virtual Task<IReadOnlyList<TemplateDefinition>> GetAllAsync()
@@ -44,7 +44,7 @@ public class StaticTemplateDefinitionStore : IStaticTemplateDefinitionStore, ISi
         return Task.FromResult<IReadOnlyList<TemplateDefinition>>(TemplateDefinitions.Value.Values.ToImmutableList());
     }
 
-    public virtual Task<TemplateDefinition> GetOrNullAsync(string name)
+    public virtual Task<TemplateDefinition?> GetOrNullAsync(string name)
     {
         return Task.FromResult(TemplateDefinitions.Value.GetOrDefault(name));
     }
@@ -57,7 +57,7 @@ public class StaticTemplateDefinitionStore : IStaticTemplateDefinitionStore, ISi
         {
             var providers = Options
                 .DefinitionProviders
-                .Select(p => scope.ServiceProvider.GetRequiredService(p) as ITemplateDefinitionProvider)
+                .Select(p => (scope.ServiceProvider.GetRequiredService(p) as ITemplateDefinitionProvider)!)
                 .ToList();
 
             var context = new TemplateDefinitionContext(templates);
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentContributorContext.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentContributorContext.cs
index 11b9af255a..8ea941114a 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentContributorContext.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentContributorContext.cs
@@ -11,13 +11,12 @@ public class TemplateContentContributorContext
     [NotNull]
     public IServiceProvider ServiceProvider { get; }
 
-    [CanBeNull]
-    public string Culture { get; }
+    public string? Culture { get; }
 
     public TemplateContentContributorContext(
         [NotNull] TemplateDefinition templateDefinition,
         [NotNull] IServiceProvider serviceProvider,
-        [CanBeNull] string culture)
+        string? culture)
     {
         TemplateDefinition = Check.NotNull(templateDefinition, nameof(templateDefinition));
         ServiceProvider = Check.NotNull(serviceProvider, nameof(serviceProvider));
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentProvider.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentProvider.cs
index 64ecd1f4c7..5c9a51be82 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentProvider.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateContentProvider.cs
@@ -26,9 +26,9 @@ public class TemplateContentProvider : ITemplateContentProvider, ITransientDepen
         _templateDefinitionManager = templateDefinitionManager;
     }
 
-    public virtual async Task<string> GetContentOrNullAsync(
+    public virtual async Task<string?> GetContentOrNullAsync(
         [NotNull] string templateName,
-        [CanBeNull] string cultureName = null,
+        string? cultureName = null,
         bool tryDefaults = true,
         bool useCurrentCultureIfCultureNameIsNull = true)
     {
@@ -36,9 +36,9 @@ public class TemplateContentProvider : ITemplateContentProvider, ITransientDepen
         return await GetContentOrNullAsync(template, cultureName);
     }
 
-    public virtual async Task<string> GetContentOrNullAsync(
+    public virtual async Task<string?> GetContentOrNullAsync(
         [NotNull] TemplateDefinition templateDefinition,
-        [CanBeNull] string cultureName = null,
+        string? cultureName = null,
         bool tryDefaults = true,
         bool useCurrentCultureIfCultureNameIsNull = true)
     {
@@ -53,7 +53,7 @@ public class TemplateContentProvider : ITemplateContentProvider, ITransientDepen
 
         using (var scope = ServiceScopeFactory.CreateScope())
         {
-            string templateString = null;
+            string? templateString = null;
 
             if (cultureName == null && useCurrentCultureIfCultureNameIsNull)
             {
@@ -151,7 +151,7 @@ public class TemplateContentProvider : ITemplateContentProvider, ITransientDepen
             .ToArray();
     }
 
-    protected virtual async Task<string> GetContentOrNullAsync(
+    protected virtual async Task<string?> GetContentOrNullAsync(
         ITemplateContentContributor[] contributors,
         TemplateContentContributorContext context)
     {
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinition.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinition.cs
index 64aeba815e..a371fc3a9a 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinition.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinition.cs
@@ -20,23 +20,19 @@ public class TemplateDefinition : IHasNameWithLocalizableDisplayName
             _displayName = value;
         }
     }
-    private ILocalizableString _displayName;
+    private ILocalizableString _displayName = default!;
 
     public bool IsLayout { get; }
 
-    [CanBeNull]
-    public string Layout { get; set; }
+    public string? Layout { get; set; }
 
-    [CanBeNull]
-    public string LocalizationResourceName { get; set; }
+    public string? LocalizationResourceName { get; set; }
 
     public bool IsInlineLocalized { get; set; }
 
-    [CanBeNull]
-    public string DefaultCultureName { get; }
+    public string? DefaultCultureName { get; }
 
-    [CanBeNull]
-    public string RenderEngine { get; set; }
+    public string? RenderEngine { get; set; }
 
     /// <summary>
     /// Gets/sets a key-value on the <see cref="Properties"/>.
@@ -46,8 +42,7 @@ public class TemplateDefinition : IHasNameWithLocalizableDisplayName
     /// Returns the value in the <see cref="Properties"/> dictionary by given <see cref="name"/>.
     /// Returns null if given <see cref="name"/> is not present in the <see cref="Properties"/> dictionary.
     /// </returns>
-    [CanBeNull]
-    public object this[string name] {
+    public object? this[string name] {
         get => Properties.GetOrDefault(name);
         set => Properties[name] = value;
     }
@@ -56,15 +51,15 @@ public class TemplateDefinition : IHasNameWithLocalizableDisplayName
     /// Can be used to get/set custom properties for this feature.
     /// </summary>
     [NotNull]
-    public Dictionary<string, object> Properties { get; }
+    public Dictionary<string, object?> Properties { get; }
 
     public TemplateDefinition(
         [NotNull] string name,
         [NotNull] Type localizationResource,
-        [CanBeNull] ILocalizableString displayName = null,
+        ILocalizableString? displayName = null,
         bool isLayout = false,
-        string layout = null,
-        string defaultCultureName = null)
+        string? layout = null,
+        string? defaultCultureName = null)
     : this(name, LocalizationResourceNameAttribute.GetName(localizationResource), displayName, isLayout, layout, defaultCultureName)
     {
 
@@ -72,11 +67,11 @@ public class TemplateDefinition : IHasNameWithLocalizableDisplayName
 
     public TemplateDefinition(
         [NotNull] string name,
-        [CanBeNull] string localizationResourceName = null,
-        [CanBeNull] ILocalizableString displayName = null,
+        string? localizationResourceName = null,
+        ILocalizableString? displayName = null,
         bool isLayout = false,
-        string layout = null,
-        string defaultCultureName = null)
+        string? layout = null,
+        string? defaultCultureName = null)
     {
         Name = Check.NotNullOrWhiteSpace(name, nameof(name), MaxNameLength);
         LocalizationResourceName = localizationResourceName;
@@ -84,7 +79,7 @@ public class TemplateDefinition : IHasNameWithLocalizableDisplayName
         IsLayout = isLayout;
         Layout = layout;
         DefaultCultureName = defaultCultureName;
-        Properties = new Dictionary<string, object>();
+        Properties = new Dictionary<string, object?>();
     }
 
     /// <summary>
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionContext.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionContext.cs
index b32332807f..9edd370ecf 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionContext.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionContext.cs
@@ -17,7 +17,7 @@ public class TemplateDefinitionContext : ITemplateDefinitionContext
         return Templates.Values.ToImmutableList();
     }
 
-    public virtual TemplateDefinition GetOrNull(string name)
+    public virtual TemplateDefinition? GetOrNull(string name)
     {
         return Templates.GetOrDefault(name);
     }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionExtensions.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionExtensions.cs
index 35cc69275d..0d830e65ef 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionExtensions.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionExtensions.cs
@@ -21,7 +21,7 @@ public static class TemplateDefinitionExtensions
         );
     }
 
-    public static string GetVirtualFilePathOrNull(
+    public static string? GetVirtualFilePathOrNull(
         [NotNull] this TemplateDefinition templateDefinition)
     {
         Check.NotNull(templateDefinition, nameof(templateDefinition));
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionManager.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionManager.cs
index 7e2920e446..32d4d8eeab 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionManager.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateDefinitionManager.cs
@@ -28,7 +28,7 @@ public class TemplateDefinitionManager : ITemplateDefinitionManager, ISingletonD
         return permission;
     }
 
-    public virtual async Task<TemplateDefinition> GetOrNullAsync(string name)
+    public virtual async Task<TemplateDefinition?> GetOrNullAsync(string name)
     {
         Check.NotNull(name, nameof(name));
 
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateRenderingEngineBase.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateRenderingEngineBase.cs
index a2c354801d..62c8dee43c 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateRenderingEngineBase.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/TemplateRenderingEngineBase.cs
@@ -22,14 +22,14 @@ public abstract class TemplateRenderingEngineBase : ITemplateRenderingEngine
         StringLocalizerFactory = stringLocalizerFactory;
     }
 
-    public abstract Task<string> RenderAsync(string templateName, object model = null, string cultureName = null, Dictionary<string, object> globalContext = null);
+    public abstract Task<string> RenderAsync(string templateName, object? model = null, string? cultureName = null, Dictionary<string, object>? globalContext = null);
 
-    protected virtual async Task<string> GetContentOrNullAsync(TemplateDefinition templateDefinition)
+    protected virtual async Task<string?> GetContentOrNullAsync(TemplateDefinition templateDefinition)
     {
         return await TemplateContentProvider.GetContentOrNullAsync(templateDefinition);
     }
 
-    protected virtual IStringLocalizer GetLocalizerOrNull(TemplateDefinition templateDefinition)
+    protected virtual IStringLocalizer? GetLocalizerOrNull(TemplateDefinition templateDefinition)
     {
         if (templateDefinition.LocalizationResourceName != null)
         {
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/FileInfoLocalizedTemplateContentReader.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/FileInfoLocalizedTemplateContentReader.cs
index 27e400c082..81074936e6 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/FileInfoLocalizedTemplateContentReader.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/FileInfoLocalizedTemplateContentReader.cs
@@ -5,8 +5,8 @@ namespace Volo.Abp.TextTemplating.VirtualFiles;
 
 public class FileInfoLocalizedTemplateContentReader : ILocalizedTemplateContentReader
 {
-    private IFileInfo _fileInfo;
-    private string _content;
+    private IFileInfo _fileInfo = default!;
+    private string _content = default!;
 
     public async Task ReadContentsAsync(IFileInfo fileInfo)
     {
@@ -14,7 +14,7 @@ public class FileInfoLocalizedTemplateContentReader : ILocalizedTemplateContentR
         _content = await fileInfo.ReadAsStringAsync();
     }
 
-    public string GetContentOrNull(string culture)
+    public string? GetContentOrNull(string? culture)
     {
         if (culture == null)
         {
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/ILocalizedTemplateContentReader.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/ILocalizedTemplateContentReader.cs
index 9fc15d1954..ab2380c069 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/ILocalizedTemplateContentReader.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/ILocalizedTemplateContentReader.cs
@@ -4,5 +4,5 @@ namespace Volo.Abp.TextTemplating.VirtualFiles;
 
 public interface ILocalizedTemplateContentReader
 {
-    public string GetContentOrNull([CanBeNull] string culture);
+    public string? GetContentOrNull(string? culture);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/NullLocalizedTemplateContentReader.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/NullLocalizedTemplateContentReader.cs
index 878428b5ef..f2988d8197 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/NullLocalizedTemplateContentReader.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/NullLocalizedTemplateContentReader.cs
@@ -9,7 +9,7 @@ public class NullLocalizedTemplateContentReader : ILocalizedTemplateContentReade
 
     }
 
-    public string GetContentOrNull(string culture)
+    public string? GetContentOrNull(string? culture)
     {
         return null;
     }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/TemplateContentFileInfo.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/TemplateContentFileInfo.cs
index 5469700432..45dbd6e553 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/TemplateContentFileInfo.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/TemplateContentFileInfo.cs
@@ -2,7 +2,7 @@ namespace Volo.Abp.TextTemplating.VirtualFiles;
 
 public class TemplateContentFileInfo
 {
-    public string FileName { get; set; }
+    public string FileName { get; set; } = default!;
 
-    public string FileContent { get; set; }
+    public string FileContent { get; set; } = default!;
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFileTemplateContentContributor.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFileTemplateContentContributor.cs
index 7bd66f2f50..999bc62de9 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFileTemplateContentContributor.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFileTemplateContentContributor.cs
@@ -15,7 +15,7 @@ public class VirtualFileTemplateContentContributor : ITemplateContentContributor
         _localizedTemplateContentReaderFactory = localizedTemplateContentReaderFactory;
     }
 
-    public virtual async Task<string> GetOrNullAsync(TemplateContentContributorContext context)
+    public virtual async Task<string?> GetOrNullAsync(TemplateContentContributorContext context)
     {
         var localizedReader = await _localizedTemplateContentReaderFactory
             .CreateAsync(context.TemplateDefinition);
diff --git a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFolderLocalizedTemplateContentReader.cs b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFolderLocalizedTemplateContentReader.cs
index 828978b1d2..0e6c9b13c2 100644
--- a/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFolderLocalizedTemplateContentReader.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Core/Volo/Abp/TextTemplating/VirtualFiles/VirtualFolderLocalizedTemplateContentReader.cs
@@ -9,7 +9,7 @@ namespace Volo.Abp.TextTemplating.VirtualFiles;
 
 public class VirtualFolderLocalizedTemplateContentReader : ILocalizedTemplateContentReader
 {
-    private Dictionary<string, TemplateContentFileInfo> _dictionary;
+    private Dictionary<string, TemplateContentFileInfo> _dictionary = default!;
     private readonly string[] _fileExtension;
 
     public VirtualFolderLocalizedTemplateContentReader(string[] fileExtension)
@@ -44,7 +44,7 @@ public class VirtualFolderLocalizedTemplateContentReader : ILocalizedTemplateCon
         }
     }
 
-    public string GetContentOrNull(string cultureName)
+    public string? GetContentOrNull(string? cultureName)
     {
         if (cultureName == null)
         {
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo.Abp.TextTemplating.Razor.csproj b/framework/src/Volo.Abp.TextTemplating.Razor/Volo.Abp.TextTemplating.Razor.csproj
index 962746bd0a..4242ca9f29 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo.Abp.TextTemplating.Razor.csproj
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo.Abp.TextTemplating.Razor.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <RootNamespace />
     </PropertyGroup>
 
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/AbpRazorTemplateCSharpCompiler.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/AbpRazorTemplateCSharpCompiler.cs
index c1dc5005b1..bdc8897ddf 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/AbpRazorTemplateCSharpCompiler.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/AbpRazorTemplateCSharpCompiler.cs
@@ -40,7 +40,7 @@ public class AbpRazorTemplateCSharpCompiler : ISingletonDependency
         .Select(x => MetadataReference.CreateFromFile(x.Location))
         .ToImmutableList();
 
-    public virtual Stream CreateAssembly(string code, string assemblyName, List<MetadataReference> references = null, CSharpCompilationOptions options = null)
+    public virtual Stream CreateAssembly(string code, string assemblyName, List<MetadataReference>? references = null, CSharpCompilationOptions? options = null)
     {
         var defaultReferences = DefaultReferences.Concat(Options.References);
         try
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/DefaultAbpRazorProjectEngineFactory.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/DefaultAbpRazorProjectEngineFactory.cs
index d15d70ded6..d17bfaea4f 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/DefaultAbpRazorProjectEngineFactory.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/DefaultAbpRazorProjectEngineFactory.cs
@@ -7,7 +7,7 @@ namespace Volo.Abp.TextTemplating.Razor;
 
 public class DefaultAbpRazorProjectEngineFactory : IAbpRazorProjectEngineFactory, ITransientDependency
 {
-    public virtual async Task<RazorProjectEngine> CreateAsync(Action<RazorProjectEngineBuilder> configure = null)
+    public virtual async Task<RazorProjectEngine> CreateAsync(Action<RazorProjectEngineBuilder>? configure = null)
     {
         return RazorProjectEngine.Create(await CreateRazorConfigurationAsync(), EmptyProjectFileSystem.Empty, configure);
     }
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/EmptyProjectFileSystem.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/EmptyProjectFileSystem.cs
index fd2b90a6b1..8c8d8703dd 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/EmptyProjectFileSystem.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/EmptyProjectFileSystem.cs
@@ -21,7 +21,7 @@ internal class EmptyProjectFileSystem : RazorProjectFileSystem
         return GetItem(path, fileKind: null);
     }
 
-    public override RazorProjectItem GetItem(string path, string fileKind)
+    public override RazorProjectItem GetItem(string path, string? fileKind)
     {
         NormalizeAndEnsureValidPath(path);
         return new NotFoundProjectItem(string.Empty, path, fileKind);
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IAbpRazorProjectEngineFactory.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IAbpRazorProjectEngineFactory.cs
index 969ce762d1..197133ef72 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IAbpRazorProjectEngineFactory.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IAbpRazorProjectEngineFactory.cs
@@ -6,5 +6,5 @@ namespace Volo.Abp.TextTemplating.Razor;
 
 public interface IAbpRazorProjectEngineFactory
 {
-    Task<RazorProjectEngine> CreateAsync(Action<RazorProjectEngineBuilder> configure = null);
+    Task<RazorProjectEngine> CreateAsync(Action<RazorProjectEngineBuilder>? configure = null);
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IRazorTemplatePage.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IRazorTemplatePage.cs
index 78b80941e9..f4b2a17006 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IRazorTemplatePage.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/IRazorTemplatePage.cs
@@ -8,24 +8,24 @@ namespace Volo.Abp.TextTemplating.Razor;
 
 public interface IRazorTemplatePage<TModel> : IRazorTemplatePage
 {
-    TModel Model { get; set; }
+    TModel? Model { get; set; }
 }
 
 public interface IRazorTemplatePage
 {
     IServiceProvider ServiceProvider { get; set; }
 
-    IStringLocalizer Localizer { get; set; }
+    IStringLocalizer? Localizer { get; set; }
 
-    HtmlEncoder HtmlEncoder { get; set; }
+    HtmlEncoder? HtmlEncoder { get; set; }
 
-    JavaScriptEncoder JavaScriptEncoder { get; set; }
+    JavaScriptEncoder? JavaScriptEncoder { get; set; }
 
-    UrlEncoder UrlEncoder { get; set; }
+    UrlEncoder? UrlEncoder { get; set; }
 
     Dictionary<string, object> GlobalContext { get; set; }
 
-    string Body { get; set; }
+    string? Body { get; set; }
 
     Task ExecuteAsync();
 
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/NotFoundProjectItem.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/NotFoundProjectItem.cs
index 5db2c8f582..2651237d2d 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/NotFoundProjectItem.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/NotFoundProjectItem.cs
@@ -6,7 +6,7 @@ namespace Volo.Abp.TextTemplating.Razor;
 
 internal class NotFoundProjectItem : RazorProjectItem
 {
-    public NotFoundProjectItem(string basePath, string path, string fileKind)
+    public NotFoundProjectItem(string basePath, string path, string? fileKind)
     {
         BasePath = basePath;
         FilePath = path;
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplatePageBase.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplatePageBase.cs
index fd2d2c13e7..a85d9d1480 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplatePageBase.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplatePageBase.cs
@@ -9,30 +9,30 @@ namespace Volo.Abp.TextTemplating.Razor;
 
 public abstract class RazorTemplatePageBase<TModel> : RazorTemplatePageBase, IRazorTemplatePage<TModel>
 {
-    public TModel Model { get; set; }
+    public TModel? Model { get; set; }
 }
 
 public abstract class RazorTemplatePageBase : IRazorTemplatePage
 {
-    public Dictionary<string, object> GlobalContext { get; set; }
+    public Dictionary<string, object> GlobalContext { get; set; } = default!;
 
-    public IServiceProvider ServiceProvider { get; set; }
+    public IServiceProvider ServiceProvider { get; set; } = default!;
 
-    public IStringLocalizer Localizer { get; set; }
+    public IStringLocalizer? Localizer { get; set; }
 
-    public HtmlEncoder HtmlEncoder { get; set; }
+    public HtmlEncoder? HtmlEncoder { get; set; }
 
-    public JavaScriptEncoder JavaScriptEncoder { get; set; }
+    public JavaScriptEncoder? JavaScriptEncoder { get; set; }
 
-    public UrlEncoder UrlEncoder { get; set; }
+    public UrlEncoder? UrlEncoder { get; set; }
 
-    public string Body { get; set; }
+    public string? Body { get; set; }
 
     private readonly StringBuilder _stringBuilder = new StringBuilder();
 
     private AttributeInfo _attributeInfo;
 
-    public virtual void WriteLiteral(string literal = null)
+    public virtual void WriteLiteral(string? literal = null)
     {
         if (!literal.IsNullOrEmpty())
         {
@@ -40,7 +40,7 @@ public abstract class RazorTemplatePageBase : IRazorTemplatePage
         }
     }
 
-    public virtual void Write(object value = null)
+    public virtual void Write(object? value = null)
     {
         if (value is null)
         {
diff --git a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplateRenderingEngine.cs b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplateRenderingEngine.cs
index 86298f2daf..2384bd8740 100644
--- a/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplateRenderingEngine.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Razor/Volo/Abp/TextTemplating/Razor/RazorTemplateRenderingEngine.cs
@@ -34,9 +34,9 @@ public class RazorTemplateRenderingEngine : TemplateRenderingEngineBase, ITransi
 
     public override async Task<string> RenderAsync(
         [NotNull] string templateName,
-        [CanBeNull] object model = null,
-        [CanBeNull] string cultureName = null,
-        [CanBeNull] Dictionary<string, object> globalContext = null)
+        object? model = null,
+        string? cultureName = null,
+        Dictionary<string, object>? globalContext = null)
     {
         Check.NotNullOrWhiteSpace(templateName, nameof(templateName));
 
@@ -70,9 +70,9 @@ public class RazorTemplateRenderingEngine : TemplateRenderingEngineBase, ITransi
 
     protected virtual async Task<string> RenderInternalAsync(
         string templateName,
-        string body,
+        string? body,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         var templateDefinition = await TemplateDefinitionManager.GetAsync(templateName);
 
@@ -97,9 +97,9 @@ public class RazorTemplateRenderingEngine : TemplateRenderingEngineBase, ITransi
 
     protected virtual async Task<string> RenderSingleTemplateAsync(
         TemplateDefinition templateDefinition,
-        string body,
+        string? body,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         return await RenderTemplateContentWithRazorAsync(
             templateDefinition,
@@ -111,13 +111,13 @@ public class RazorTemplateRenderingEngine : TemplateRenderingEngineBase, ITransi
 
     protected virtual async Task<string> RenderTemplateContentWithRazorAsync(
         TemplateDefinition templateDefinition,
-        string body,
+        string? body,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         var assembly = await AbpCompiledViewProvider.GetAssemblyAsync(templateDefinition);
-        var templateType = assembly.GetType(AbpRazorTemplateConsts.TypeName);
-        var template = (IRazorTemplatePage)Activator.CreateInstance(templateType);
+        var templateType = assembly.GetType(AbpRazorTemplateConsts.TypeName)!;
+        var template = (IRazorTemplatePage)Activator.CreateInstance(templateType)!;
 
         using (var scope = ServiceScopeFactory.CreateScope())
         {
@@ -147,11 +147,11 @@ public class RazorTemplateRenderingEngine : TemplateRenderingEngineBase, ITransi
         }
     }
 
-    private void SetModel<TModel>(IRazorTemplatePage razorTemplatePage, object model = null)
+    private void SetModel<TModel>(IRazorTemplatePage razorTemplatePage, object? model = null)
     {
         if (razorTemplatePage is IRazorTemplatePage<TModel> razorTemplatePageWithModel)
         {
-            razorTemplatePageWithModel.Model = (TModel)model;
+            razorTemplatePageWithModel.Model = (TModel?)model;
         }
     }
 }
diff --git a/framework/src/Volo.Abp.TextTemplating.Scriban/Volo.Abp.TextTemplating.Scriban.csproj b/framework/src/Volo.Abp.TextTemplating.Scriban/Volo.Abp.TextTemplating.Scriban.csproj
index d18d90c8f9..ea1d0f0f8d 100644
--- a/framework/src/Volo.Abp.TextTemplating.Scriban/Volo.Abp.TextTemplating.Scriban.csproj
+++ b/framework/src/Volo.Abp.TextTemplating.Scriban/Volo.Abp.TextTemplating.Scriban.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <RootNamespace />
     </PropertyGroup>
 
diff --git a/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateLocalizer.cs b/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateLocalizer.cs
index 91af004cf9..6bf32d1a58 100644
--- a/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateLocalizer.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateLocalizer.cs
@@ -44,7 +44,7 @@ public class ScribanTemplateLocalizer : IScriptCustomFunction
         }
 
         var args = arguments.Skip(1).Where(x => x != null && !x.ToString().IsNullOrWhiteSpace()).ToArray();
-        return args.Any() ? _localizer[name.ToString(), args] : _localizer[name.ToString()];
+        return args.Any() ? _localizer[name.ToString()!, args] : _localizer[name.ToString()!];
     }
 
     public int RequiredParameterCount => 1;
diff --git a/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateRenderingEngine.cs b/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateRenderingEngine.cs
index a4da669893..7a5ac79592 100644
--- a/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateRenderingEngine.cs
+++ b/framework/src/Volo.Abp.TextTemplating.Scriban/Volo/Abp/TextTemplating/Scriban/ScribanTemplateRenderingEngine.cs
@@ -24,9 +24,9 @@ public class ScribanTemplateRenderingEngine : TemplateRenderingEngineBase, ITran
 
     public override async Task<string> RenderAsync(
         [NotNull] string templateName,
-        [CanBeNull] object model = null,
-        [CanBeNull] string cultureName = null,
-        [CanBeNull] Dictionary<string, object> globalContext = null)
+        object? model = null,
+        string? cultureName = null,
+        Dictionary<string, object>? globalContext = null)
     {
         Check.NotNullOrWhiteSpace(templateName, nameof(templateName));
 
@@ -59,7 +59,7 @@ public class ScribanTemplateRenderingEngine : TemplateRenderingEngineBase, ITran
     protected virtual async Task<string> RenderInternalAsync(
         string templateName,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         var templateDefinition = await TemplateDefinitionManager.GetAsync(templateName);
 
@@ -84,13 +84,13 @@ public class ScribanTemplateRenderingEngine : TemplateRenderingEngineBase, ITran
     protected virtual async Task<string> RenderSingleTemplateAsync(
         TemplateDefinition templateDefinition,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         var rawTemplateContent = await GetContentOrNullAsync(templateDefinition);
 
         return await RenderTemplateContentWithScribanAsync(
             templateDefinition,
-            rawTemplateContent,
+            rawTemplateContent!,
             globalContext,
             model
         );
@@ -100,7 +100,7 @@ public class ScribanTemplateRenderingEngine : TemplateRenderingEngineBase, ITran
         TemplateDefinition templateDefinition,
         string templateContent,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         var context = CreateScribanTemplateContext(
             templateDefinition,
@@ -116,7 +116,7 @@ public class ScribanTemplateRenderingEngine : TemplateRenderingEngineBase, ITran
     protected virtual TemplateContext CreateScribanTemplateContext(
         TemplateDefinition templateDefinition,
         Dictionary<string, object> globalContext,
-        object model = null)
+        object? model = null)
     {
         var context = new TemplateContext();
 
diff --git a/framework/src/Volo.Abp.TextTemplating/Volo.Abp.TextTemplating.csproj b/framework/src/Volo.Abp.TextTemplating/Volo.Abp.TextTemplating.csproj
index 27907183c0..f8d1d85192 100644
--- a/framework/src/Volo.Abp.TextTemplating/Volo.Abp.TextTemplating.csproj
+++ b/framework/src/Volo.Abp.TextTemplating/Volo.Abp.TextTemplating.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <RootNamespace />
   </PropertyGroup>