diff --git a/framework/src/Volo.Abp.AzureServiceBus/Volo.Abp.AzureServiceBus.csproj b/framework/src/Volo.Abp.AzureServiceBus/Volo.Abp.AzureServiceBus.csproj
index 98a67869cf..aef38c1e10 100644
--- a/framework/src/Volo.Abp.AzureServiceBus/Volo.Abp.AzureServiceBus.csproj
+++ b/framework/src/Volo.Abp.AzureServiceBus/Volo.Abp.AzureServiceBus.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <AssemblyName>Volo.Abp.AzureServiceBus</AssemblyName>
         <PackageId>Volo.Abp.AzureServiceBus</PackageId>
         <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/AzureServiceBusMessageConsumer.cs b/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/AzureServiceBusMessageConsumer.cs
index 71143b834e..4417a6ef79 100644
--- a/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/AzureServiceBusMessageConsumer.cs
+++ b/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/AzureServiceBusMessageConsumer.cs
@@ -20,9 +20,9 @@ public class AzureServiceBusMessageConsumer : IAzureServiceBusMessageConsumer, I
     private readonly IExceptionNotifier _exceptionNotifier;
     private readonly IProcessorPool _processorPool;
     private readonly ConcurrentBag<Func<ServiceBusReceivedMessage, Task>> _callbacks;
-    private string _connectionName;
-    private string _subscriptionName;
-    private string _topicName;
+    private string _connectionName = default!;
+    private string _subscriptionName = default!;
+    private string _topicName = default!;
 
     public AzureServiceBusMessageConsumer(
         IExceptionNotifier exceptionNotifier,
@@ -37,7 +37,7 @@ public class AzureServiceBusMessageConsumer : IAzureServiceBusMessageConsumer, I
     public virtual void Initialize(
         [NotNull] string topicName,
         [NotNull] string subscriptionName,
-        string connectionName)
+        string? connectionName)
     {
         Check.NotNull(topicName, nameof(topicName));
         Check.NotNull(subscriptionName, nameof(subscriptionName));
diff --git a/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/ClientConfig.cs b/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/ClientConfig.cs
index 9b9cbd6843..02b8397917 100644
--- a/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/ClientConfig.cs
+++ b/framework/src/Volo.Abp.AzureServiceBus/Volo/Abp/AzureServiceBus/ClientConfig.cs
@@ -5,7 +5,7 @@ namespace Volo.Abp.AzureServiceBus;
 
 public class ClientConfig
 {
-    public string ConnectionString { get; set; }
+    public string ConnectionString { get; set; } = default!;
 
     public ServiceBusAdministrationClientOptions Admin { get; set; } = new();
 
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo.Abp.BackgroundJobs.Abstractions.csproj b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo.Abp.BackgroundJobs.Abstractions.csproj
index 3633fd45e3..e12574e992 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo.Abp.BackgroundJobs.Abstractions.csproj
+++ b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo.Abp.BackgroundJobs.Abstractions.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundJobs.Abstractions</AssemblyName>
     <PackageId>Volo.Abp.BackgroundJobs.Abstractions</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecuter.cs b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecuter.cs
index 7798a8d9a6..6b6d822c50 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecuter.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecuter.cs
@@ -54,7 +54,7 @@ public class BackgroundJobExecuter : IBackgroundJobExecuter, ITransientDependenc
                 {
                     if (jobExecuteMethod.Name == nameof(IAsyncBackgroundJob<object>.ExecuteAsync))
                     {
-                        await ((Task)jobExecuteMethod.Invoke(job, new[] { context.JobArgs }));
+                        await ((Task)jobExecuteMethod.Invoke(job, new[] { context.JobArgs })!);
                     }
                     else
                     {
@@ -74,7 +74,7 @@ public class BackgroundJobExecuter : IBackgroundJobExecuter, ITransientDependenc
 
             throw new BackgroundJobExecutionException("A background job execution is failed. See inner exception for details.", ex)
             {
-                JobType = context.JobType.AssemblyQualifiedName,
+                JobType = context.JobType.AssemblyQualifiedName!,
                 JobArgs = context.JobArgs
             };
         }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecutionException.cs b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecutionException.cs
index 6c2df10a4f..f8c98437dc 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecutionException.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobExecutionException.cs
@@ -6,9 +6,9 @@ namespace Volo.Abp.BackgroundJobs;
 [Serializable]
 public class BackgroundJobExecutionException : AbpException
 {
-    public string JobType { get; set; }
+    public string JobType { get; set; } = default!;
 
-    public object JobArgs { get; set; }
+    public object JobArgs { get; set; } = default!;
 
     public BackgroundJobExecutionException()
     {
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobNameAttribute.cs b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobNameAttribute.cs
index edac395039..012569c423 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobNameAttribute.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Abstractions/Volo/Abp/BackgroundJobs/BackgroundJobNameAttribute.cs
@@ -22,11 +22,11 @@ public class BackgroundJobNameAttribute : Attribute, IBackgroundJobNameProvider
     {
         Check.NotNull(jobArgsType, nameof(jobArgsType));
 
-        return jobArgsType
-                   .GetCustomAttributes(true)
-                   .OfType<IBackgroundJobNameProvider>()
-                   .FirstOrDefault()
-                   ?.Name
-               ?? jobArgsType.FullName;
+        return (jobArgsType
+                    .GetCustomAttributes(true)
+                    .OfType<IBackgroundJobNameProvider>()
+                    .FirstOrDefault()
+                    ?.Name
+                ?? jobArgsType.FullName)!;
     }
 }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo.Abp.BackgroundJobs.HangFire.csproj b/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo.Abp.BackgroundJobs.HangFire.csproj
index 5823174e54..8e79738248 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo.Abp.BackgroundJobs.HangFire.csproj
+++ b/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo.Abp.BackgroundJobs.HangFire.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundJobs.HangFire</AssemblyName>
     <PackageId>Volo.Abp.BackgroundJobs.HangFire</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/AbpBackgroundJobsHangfireModule.cs b/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/AbpBackgroundJobsHangfireModule.cs
index ce2babaabc..ca874cd701 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/AbpBackgroundJobsHangfireModule.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/AbpBackgroundJobsHangfireModule.cs
@@ -30,7 +30,7 @@ public class AbpBackgroundJobsHangfireModule : AbpModule
         }
     }
 
-    private BackgroundJobServer CreateOnlyEnqueueJobServer(IServiceProvider serviceProvider)
+    private BackgroundJobServer? CreateOnlyEnqueueJobServer(IServiceProvider serviceProvider)
     {
         serviceProvider.GetRequiredService<JobStorage>();
         return null;
diff --git a/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/HangfireJobExecutionAdapter.cs b/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/HangfireJobExecutionAdapter.cs
index 58d2863618..8790243334 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/HangfireJobExecutionAdapter.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.HangFire/Volo/Abp/BackgroundJobs/Hangfire/HangfireJobExecutionAdapter.cs
@@ -39,7 +39,7 @@ public class HangfireJobExecutionAdapter<TArgs>
         using (var scope = ServiceScopeFactory.CreateScope())
         {
             var jobType = Options.GetJob(typeof(TArgs)).JobType;
-            var context = new JobExecutionContext(scope.ServiceProvider, jobType, args, cancellationToken: cancellationToken);
+            var context = new JobExecutionContext(scope.ServiceProvider, jobType, args!, cancellationToken: cancellationToken);
             await JobExecuter.ExecuteAsync(context);
         }
     }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo.Abp.BackgroundJobs.Quartz.csproj b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo.Abp.BackgroundJobs.Quartz.csproj
index 1326926d55..47847d00c8 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo.Abp.BackgroundJobs.Quartz.csproj
+++ b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo.Abp.BackgroundJobs.Quartz.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundJobs.Quartz</AssemblyName>
     <PackageId>Volo.Abp.BackgroundJobs.Quartz</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobQuartzOptions.cs b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobQuartzOptions.cs
index fb0a7bb406..2aac41e885 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobQuartzOptions.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobQuartzOptions.cs
@@ -30,7 +30,7 @@ public class AbpBackgroundJobQuartzOptions
     {
         exception.RefireImmediately = true;
 
-        var retryCount = executionContext.JobDetail.JobDataMap.GetString(QuartzBackgroundJobManager.JobDataPrefix + nameof(RetryCount)).To<int>();
+        var retryCount = executionContext.JobDetail.JobDataMap.GetString(QuartzBackgroundJobManager.JobDataPrefix + nameof(RetryCount))!.To<int>();
         if (retryIndex > retryCount)
         {
             exception.RefireImmediately = false;
@@ -38,7 +38,7 @@ public class AbpBackgroundJobQuartzOptions
             return;
         }
 
-        var retryInterval = executionContext.JobDetail.JobDataMap.GetString(QuartzBackgroundJobManager.JobDataPrefix + nameof(RetryIntervalMillisecond)).To<int>();
+        var retryInterval = executionContext.JobDetail.JobDataMap.GetString(QuartzBackgroundJobManager.JobDataPrefix + nameof(RetryIntervalMillisecond))!.To<int>();
         await Task.Delay(retryInterval);
     }
 }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobsQuartzModule.cs b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobsQuartzModule.cs
index 500cc8538e..6b2d8f36e0 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobsQuartzModule.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/AbpBackgroundJobsQuartzModule.cs
@@ -19,10 +19,10 @@ public class AbpBackgroundJobsQuartzModule : AbpModule
 
     public override void OnPreApplicationInitialization(ApplicationInitializationContext context)
     {
-        var options = context.ServiceProvider.GetService<IOptions<AbpBackgroundJobOptions>>().Value;
+        var options = context.ServiceProvider.GetRequiredService<IOptions<AbpBackgroundJobOptions>>().Value;
         if (!options.IsJobExecutionEnabled)
         {
-            var quartzOptions = context.ServiceProvider.GetService<IOptions<AbpQuartzOptions>>().Value;
+            var quartzOptions = context.ServiceProvider.GetRequiredService<IOptions<AbpQuartzOptions>>().Value;
             quartzOptions.StartSchedulerFactory = scheduler => Task.CompletedTask;
         }
     }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManageExtensions.cs b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManageExtensions.cs
index 9eaa40574c..5c1e883888 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManageExtensions.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManageExtensions.cs
@@ -6,7 +6,7 @@ namespace Volo.Abp.BackgroundJobs.Quartz;
 
 public static class QuartzBackgroundJobManageExtensions
 {
-    public static async Task<string> EnqueueAsync<TArgs>(this IBackgroundJobManager backgroundJobManager,
+    public static async Task<string?> EnqueueAsync<TArgs>(this IBackgroundJobManager backgroundJobManager,
         TArgs args, int retryCount, int retryIntervalMillisecond,
         BackgroundJobPriority priority = BackgroundJobPriority.Normal, TimeSpan? delay = null)
     {
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManager.cs b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManager.cs
index 99ef72adf6..135c2fc6f7 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManager.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzBackgroundJobManager.cs
@@ -37,7 +37,7 @@ public class QuartzBackgroundJobManager : IBackgroundJobManager, ITransientDepen
     {
         var jobDataMap = new JobDataMap
             {
-                {nameof(TArgs), JsonSerializer.Serialize(args)},
+                {nameof(TArgs), JsonSerializer.Serialize(args!)},
                 {JobDataPrefix+ nameof(Options.RetryCount), retryCount.ToString()},
                 {JobDataPrefix+ nameof(Options.RetryIntervalMillisecond), retryIntervalMillisecond.ToString()},
                 {JobDataPrefix+ RetryIndex, "0"}
diff --git a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzJobExecutionAdapter.cs b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzJobExecutionAdapter.cs
index 588e844153..9005164043 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzJobExecutionAdapter.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.Quartz/Volo/Abp/BackgroundJobs/Quartz/QuartzJobExecutionAdapter.cs
@@ -38,9 +38,9 @@ public class QuartzJobExecutionAdapter<TArgs> : IJob
     {
         using (var scope = ServiceScopeFactory.CreateScope())
         {
-            var args = JsonSerializer.Deserialize<TArgs>(context.JobDetail.JobDataMap.GetString(nameof(TArgs)));
+            var args = JsonSerializer.Deserialize<TArgs>(context.JobDetail.JobDataMap.GetString(nameof(TArgs))!);
             var jobType = Options.GetJob(typeof(TArgs)).JobType;
-            var jobContext = new JobExecutionContext(scope.ServiceProvider, jobType, args, cancellationToken: context.CancellationToken);
+            var jobContext = new JobExecutionContext(scope.ServiceProvider, jobType, args!, cancellationToken: context.CancellationToken);
             try
             {
                 await JobExecuter.ExecuteAsync(jobContext);
@@ -49,7 +49,7 @@ public class QuartzJobExecutionAdapter<TArgs> : IJob
             {
                 var jobExecutionException = new JobExecutionException(exception);
 
-                var retryIndex = context.JobDetail.JobDataMap.GetString(QuartzBackgroundJobManager.JobDataPrefix + QuartzBackgroundJobManager.RetryIndex).To<int>();
+                var retryIndex = context.JobDetail.JobDataMap.GetString(QuartzBackgroundJobManager.JobDataPrefix + QuartzBackgroundJobManager.RetryIndex)!.To<int>();
                 retryIndex++;
                 context.JobDetail.JobDataMap.Put(QuartzBackgroundJobManager.JobDataPrefix + QuartzBackgroundJobManager.RetryIndex, retryIndex.ToString());
 
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo.Abp.BackgroundJobs.RabbitMQ.csproj b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo.Abp.BackgroundJobs.RabbitMQ.csproj
index 40f87898ba..c4675f6039 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo.Abp.BackgroundJobs.RabbitMQ.csproj
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo.Abp.BackgroundJobs.RabbitMQ.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundJobs.RabbitMQ</AssemblyName>
     <PackageId>Volo.Abp.BackgroundJobs.RabbitMQ</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/IJobQueue.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/IJobQueue.cs
index b244707f04..b285f598cc 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/IJobQueue.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/IJobQueue.cs
@@ -6,7 +6,7 @@ namespace Volo.Abp.BackgroundJobs.RabbitMQ;
 
 public interface IJobQueue<in TArgs> : IRunnable, IDisposable
 {
-    Task<string> EnqueueAsync(
+    Task<string?> EnqueueAsync(
         TArgs args,
         BackgroundJobPriority priority = BackgroundJobPriority.Normal,
         TimeSpan? delay = null
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs
index 9c3bf26e62..9947ba64ac 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs
@@ -21,8 +21,8 @@ public class JobQueue<TArgs> : IJobQueue<TArgs>
 
     protected BackgroundJobConfiguration JobConfiguration { get; }
     protected JobQueueConfiguration QueueConfiguration { get; }
-    protected IChannelAccessor ChannelAccessor { get; private set; }
-    protected AsyncEventingBasicConsumer Consumer { get; private set; }
+    protected IChannelAccessor? ChannelAccessor { get; private set; }
+    protected AsyncEventingBasicConsumer? Consumer { get; private set; }
 
     public ILogger<JobQueue<TArgs>> Logger { get; set; }
 
@@ -71,7 +71,7 @@ public class JobQueue<TArgs> : IJobQueue<TArgs>
                );
     }
 
-    public virtual async Task<string> EnqueueAsync(
+    public virtual async Task<string?> EnqueueAsync(
         TArgs args,
         BackgroundJobPriority priority = BackgroundJobPriority.Normal,
         TimeSpan? delay = null)
@@ -176,11 +176,11 @@ public class JobQueue<TArgs> : IJobQueue<TArgs>
             basicProperties.Expiration = delay.Value.TotalMilliseconds.ToString();
         }
 
-        ChannelAccessor.Channel.BasicPublish(
+        ChannelAccessor!.Channel.BasicPublish(
             exchange: "",
             routingKey: routingKey,
             basicProperties: basicProperties,
-            body: Serializer.Serialize(args)
+            body: Serializer.Serialize(args!)
         );
 
         return Task.CompletedTask;
@@ -188,7 +188,7 @@ public class JobQueue<TArgs> : IJobQueue<TArgs>
 
     protected virtual IBasicProperties CreateBasicPropertiesToPublish()
     {
-        var properties = ChannelAccessor.Channel.CreateBasicProperties();
+        var properties = ChannelAccessor!.Channel.CreateBasicProperties();
         properties.Persistent = true;
         return properties;
     }
@@ -206,17 +206,17 @@ public class JobQueue<TArgs> : IJobQueue<TArgs>
             try
             {
                 await JobExecuter.ExecuteAsync(context);
-                ChannelAccessor.Channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
+                ChannelAccessor!.Channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
             }
             catch (BackgroundJobExecutionException)
             {
                 //TODO: Reject like that?
-                ChannelAccessor.Channel.BasicReject(deliveryTag: ea.DeliveryTag, requeue: true);
+                ChannelAccessor!.Channel.BasicReject(deliveryTag: ea.DeliveryTag, requeue: true);
             }
             catch (Exception)
             {
                 //TODO: Reject like that?
-                ChannelAccessor.Channel.BasicReject(deliveryTag: ea.DeliveryTag, requeue: false);
+                ChannelAccessor!.Channel.BasicReject(deliveryTag: ea.DeliveryTag, requeue: false);
             }
         }
     }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs
index ee706ab864..9425cd0604 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs
@@ -9,7 +9,7 @@ public class JobQueueConfiguration : QueueDeclareConfiguration
 {
     public Type JobArgsType { get; }
 
-    public string ConnectionName { get; set; }
+    public string? ConnectionName { get; set; }
 
     public string DelayedQueueName { get; set; }
 
@@ -17,7 +17,7 @@ public class JobQueueConfiguration : QueueDeclareConfiguration
         Type jobArgsType,
         string queueName,
         string delayedQueueName,
-        string connectionName = null,
+        string? connectionName = null,
         bool durable = true,
         bool exclusive = false,
         bool autoDelete = false,
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/RabbitMqBackgroundJobManager.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/RabbitMqBackgroundJobManager.cs
index ae550077e0..d81b2758b0 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/RabbitMqBackgroundJobManager.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/RabbitMqBackgroundJobManager.cs
@@ -20,6 +20,6 @@ public class RabbitMqBackgroundJobManager : IBackgroundJobManager, ITransientDep
         TimeSpan? delay = null)
     {
         var jobQueue = await _jobQueueManager.GetAsync<TArgs>();
-        return await jobQueue.EnqueueAsync(args, priority, delay);
+        return (await jobQueue.EnqueueAsync(args, priority, delay))!;
     }
 }
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj b/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj
index 0ef692a9f2..29a4ed2edc 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo.Abp.BackgroundJobs.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundJobs</AssemblyName>
     <PackageId>Volo.Abp.BackgroundJobs</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs
index deba940d12..0d5441a4bc 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobInfo.cs
@@ -12,12 +12,12 @@ public class BackgroundJobInfo
     /// <summary>
     /// Name of the job.
     /// </summary>
-    public virtual string JobName { get; set; }
+    public virtual string JobName { get; set; } = default!;
 
     /// <summary>
     /// Job arguments as serialized to string.
     /// </summary>
-    public virtual string JobArgs { get; set; }
+    public virtual string JobArgs { get; set; } = default!;
 
     /// <summary>
     /// Try count of this job.
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
index a222f91362..7218776cfe 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
@@ -32,7 +32,7 @@ public class DefaultBackgroundJobManager : IBackgroundJobManager, ITransientDepe
     public virtual async Task<string> EnqueueAsync<TArgs>(TArgs args, BackgroundJobPriority priority = BackgroundJobPriority.Normal, TimeSpan? delay = null)
     {
         var jobName = BackgroundJobNameAttribute.GetName<TArgs>();
-        var jobId = await EnqueueAsync(jobName, args, priority, delay);
+        var jobId = await EnqueueAsync(jobName, args!, priority, delay);
         return jobId.ToString();
     }
 
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs
index 726d65d513..7abbc188ce 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/InMemoryBackgroundJobStore.cs
@@ -25,7 +25,7 @@ public class InMemoryBackgroundJobStore : IBackgroundJobStore, ISingletonDepende
 
     public virtual Task<BackgroundJobInfo> FindAsync(Guid jobId)
     {
-        return Task.FromResult(_jobs.GetOrDefault(jobId));
+        return Task.FromResult(_jobs.GetOrDefault(jobId))!;
     }
 
     public virtual Task InsertAsync(BackgroundJobInfo jobInfo)
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo.Abp.BackgroundWorkers.Hangfire.csproj b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo.Abp.BackgroundWorkers.Hangfire.csproj
index 9792dbf1ff..bec3d235e6 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo.Abp.BackgroundWorkers.Hangfire.csproj
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo.Abp.BackgroundWorkers.Hangfire.csproj
@@ -5,6 +5,8 @@
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+        <Nullable>enable</Nullable>
+        <WarningsAsErrors>Nullable</WarningsAsErrors>
         <AssemblyName>Volo.Abp.BackgroundWorkers.Hangfire</AssemblyName>
         <PackageId>Volo.Abp.BackgroundWorkers.Hangfire</PackageId>
         <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/AbpBackgroundWorkersHangfireModule.cs b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/AbpBackgroundWorkersHangfireModule.cs
index 50f43736ff..afe9a90a8a 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/AbpBackgroundWorkersHangfireModule.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/AbpBackgroundWorkersHangfireModule.cs
@@ -38,7 +38,7 @@ public class AbpBackgroundWorkersHangfireModule : AbpModule
         AsyncHelper.RunSync(() => OnPreApplicationInitializationAsync(context));
     }
     
-    private BackgroundJobServer CreateOnlyEnqueueJobServer(IServiceProvider serviceProvider)
+    private BackgroundJobServer? CreateOnlyEnqueueJobServer(IServiceProvider serviceProvider)
     {
         serviceProvider.GetRequiredService<JobStorage>();
         return null;
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerBase.cs b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerBase.cs
index c4cf1d6be0..e5cef1ce42 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerBase.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerBase.cs
@@ -6,11 +6,11 @@ namespace Volo.Abp.BackgroundWorkers.Hangfire;
 
 public abstract class HangfireBackgroundWorkerBase : BackgroundWorkerBase, IHangfireBackgroundWorker
 {
-    public string RecurringJobId { get; set; }
+    public string? RecurringJobId { get; set; }
 
-    public string CronExpression { get; set; }
+    public string CronExpression { get; set; } = default!;
 
-    public TimeZoneInfo TimeZone { get; set; }
+    public TimeZoneInfo? TimeZone { get; set; }
 
     public string Queue { get; set; }
 
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerManager.cs b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerManager.cs
index 594f01343e..4b6582d03d 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerManager.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfireBackgroundWorkerManager.cs
@@ -14,7 +14,7 @@ namespace Volo.Abp.BackgroundWorkers.Hangfire;
 [Dependency(ReplaceServices = true)]
 public class HangfireBackgroundWorkerManager : BackgroundWorkerManager, ISingletonDependency
 {
-    protected AbpHangfireBackgroundJobServer BackgroundJobServer { get; set; }
+    protected AbpHangfireBackgroundJobServer BackgroundJobServer { get; set; } = default!;
     protected IServiceProvider ServiceProvider { get; }
 
     public HangfireBackgroundWorkerManager(IServiceProvider serviceProvider)
@@ -57,7 +57,7 @@ public class HangfireBackgroundWorkerManager : BackgroundWorkerManager, ISinglet
                 var timer = worker.GetType()
                     .GetProperty("Timer", BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(worker);
 
-                var period = worker is AsyncPeriodicBackgroundWorkerBase ? ((AbpAsyncTimer)timer)?.Period : ((AbpTimer)timer)?.Period;
+                var period = worker is AsyncPeriodicBackgroundWorkerBase ? ((AbpAsyncTimer?)timer)?.Period : ((AbpTimer?)timer)?.Period;
 
                 if (period == null)
                 {
@@ -65,7 +65,7 @@ public class HangfireBackgroundWorkerManager : BackgroundWorkerManager, ISinglet
                 }
 
                 var adapterType = typeof(HangfirePeriodicBackgroundWorkerAdapter<>).MakeGenericType(ProxyHelper.GetUnProxiedType(worker));
-                var workerAdapter = Activator.CreateInstance(adapterType) as IHangfireBackgroundWorker;
+                var workerAdapter = (Activator.CreateInstance(adapterType) as IHangfireBackgroundWorker)!;
 
                 RecurringJob.AddOrUpdate(() => workerAdapter.DoWorkAsync(cancellationToken), GetCron(period.Value), workerAdapter.TimeZone, workerAdapter.Queue);
 
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfirePeriodicBackgroundWorkerAdapter.cs b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfirePeriodicBackgroundWorkerAdapter.cs
index e1cec7da85..d624966fe4 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfirePeriodicBackgroundWorkerAdapter.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/HangfirePeriodicBackgroundWorkerAdapter.cs
@@ -14,8 +14,8 @@ public class HangfirePeriodicBackgroundWorkerAdapter<TWorker> : HangfireBackgrou
     public HangfirePeriodicBackgroundWorkerAdapter()
     {
         _doWorkAsyncMethod =
-            typeof(TWorker).GetMethod("DoWorkAsync", BindingFlags.Instance | BindingFlags.NonPublic);
-        _doWorkMethod = typeof(TWorker).GetMethod("DoWork", BindingFlags.Instance | BindingFlags.NonPublic);
+            typeof(TWorker).GetMethod("DoWorkAsync", BindingFlags.Instance | BindingFlags.NonPublic)!;
+        _doWorkMethod = typeof(TWorker).GetMethod("DoWork", BindingFlags.Instance | BindingFlags.NonPublic)!;
     }
 
     public async override Task DoWorkAsync(CancellationToken cancellationToken = default)
@@ -26,7 +26,7 @@ public class HangfirePeriodicBackgroundWorkerAdapter<TWorker> : HangfireBackgrou
         switch (worker)
         {
             case AsyncPeriodicBackgroundWorkerBase asyncPeriodicBackgroundWorker:
-                await (Task)_doWorkAsyncMethod.Invoke(asyncPeriodicBackgroundWorker, new object[] { workerContext });
+                await (Task)(_doWorkAsyncMethod.Invoke(asyncPeriodicBackgroundWorker, new object[] { workerContext })!);
                 break;
             case PeriodicBackgroundWorkerBase periodicBackgroundWorker:
                 _doWorkMethod.Invoke(periodicBackgroundWorker, new object[] { workerContext });
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/IHangfireBackgroundWorker.cs b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/IHangfireBackgroundWorker.cs
index 883f488684..4371ceb8b3 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/IHangfireBackgroundWorker.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Hangfire/Volo/Abp/BackgroundWorkers/Hangfire/IHangfireBackgroundWorker.cs
@@ -6,11 +6,11 @@ namespace Volo.Abp.BackgroundWorkers.Hangfire;
 
 public interface IHangfireBackgroundWorker : IBackgroundWorker
 {
-    string RecurringJobId { get; set; }
+    string? RecurringJobId { get; set; }
 
     string CronExpression { get; set; }
 
-    TimeZoneInfo TimeZone  { get; set; }
+    TimeZoneInfo? TimeZone  { get; set; }
 
     string Queue  { get; set; }
 
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo.Abp.BackgroundWorkers.Quartz.csproj b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo.Abp.BackgroundWorkers.Quartz.csproj
index 2c43a121d1..0f4d807456 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo.Abp.BackgroundWorkers.Quartz.csproj
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo.Abp.BackgroundWorkers.Quartz.csproj
@@ -6,6 +6,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundWorkers.Quartz</AssemblyName>
     <PackageId>Volo.Abp.BackgroundWorkers.Quartz</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/IQuartzBackgroundWorker.cs b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/IQuartzBackgroundWorker.cs
index 1e96efbe45..23ba05bc94 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/IQuartzBackgroundWorker.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/IQuartzBackgroundWorker.cs
@@ -12,5 +12,5 @@ public interface IQuartzBackgroundWorker : IBackgroundWorker, IJob
 
     bool AutoRegister { get; set; }
 
-    Func<IScheduler, Task> ScheduleJob { get; set; }
+    Func<IScheduler, Task>? ScheduleJob { get; set; }
 }
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzBackgroundWorkerBase.cs b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzBackgroundWorkerBase.cs
index 0956dc2218..2ba8f6d8bd 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzBackgroundWorkerBase.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzBackgroundWorkerBase.cs
@@ -6,13 +6,13 @@ namespace Volo.Abp.BackgroundWorkers.Quartz;
 
 public abstract class QuartzBackgroundWorkerBase : BackgroundWorkerBase, IQuartzBackgroundWorker
 {
-    public ITrigger Trigger { get; set; }
+    public ITrigger Trigger { get; set; } = default!;
 
-    public IJobDetail JobDetail { get; set; }
+    public IJobDetail JobDetail { get; set; } = default!;
 
     public bool AutoRegister { get; set; } = true;
 
-    public Func<IScheduler, Task> ScheduleJob { get; set; } = null;
+    public Func<IScheduler, Task>? ScheduleJob { get; set; } = null;
 
     public abstract Task Execute(IJobExecutionContext context);
 }
diff --git a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzPeriodicBackgroundWorkerAdapter.cs b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzPeriodicBackgroundWorkerAdapter.cs
index fb94408bfe..767ac36412 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzPeriodicBackgroundWorkerAdapter.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers.Quartz/Volo/Abp/BackgroundWorkers/Quartz/QuartzPeriodicBackgroundWorkerAdapter.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Reflection;
 using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
 using Quartz;
 using Volo.Abp.DynamicProxy;
 using Volo.Abp.Threading;
@@ -12,8 +13,8 @@ public class QuartzPeriodicBackgroundWorkerAdapter<TWorker> : QuartzBackgroundWo
     IQuartzBackgroundWorkerAdapter
     where TWorker : IBackgroundWorker
 {
-    private readonly MethodInfo _doWorkAsyncMethod;
-    private readonly MethodInfo _doWorkMethod;
+    private readonly MethodInfo? _doWorkAsyncMethod;
+    private readonly MethodInfo? _doWorkMethod;
 
     public QuartzPeriodicBackgroundWorkerAdapter()
     {
@@ -40,11 +41,11 @@ public class QuartzPeriodicBackgroundWorkerAdapter<TWorker> : QuartzBackgroundWo
 
             if (worker is AsyncPeriodicBackgroundWorkerBase)
             {
-                period = ((AbpAsyncTimer)timer)?.Period;
+                period = ((AbpAsyncTimer?)timer)?.Period;
             }
             else
             {
-                period = ((AbpTimer)timer)?.Period;
+                period = ((AbpTimer?)timer)?.Period;
             }
         }
         else
@@ -59,17 +60,17 @@ public class QuartzPeriodicBackgroundWorkerAdapter<TWorker> : QuartzBackgroundWo
 
         JobDetail = JobBuilder
             .Create<QuartzPeriodicBackgroundWorkerAdapter<TWorker>>()
-            .WithIdentity(workerType.FullName)
+            .WithIdentity(workerType.FullName!)
             .Build();
         Trigger = TriggerBuilder.Create()
-            .WithIdentity(workerType.FullName)
+            .WithIdentity(workerType.FullName!)
             .WithSimpleSchedule(builder => builder.WithInterval(TimeSpan.FromMilliseconds(period.Value)).RepeatForever())
             .Build();
     }
 
     public async override Task Execute(IJobExecutionContext context)
     {
-        var worker = (IBackgroundWorker) ServiceProvider.GetService(typeof(TWorker));
+        var worker = (IBackgroundWorker) ServiceProvider.GetRequiredService(typeof(TWorker));
         var workerContext = new PeriodicBackgroundWorkerContext(ServiceProvider, context.CancellationToken);
 
         switch (worker)
@@ -78,7 +79,7 @@ public class QuartzPeriodicBackgroundWorkerAdapter<TWorker> : QuartzBackgroundWo
             {
                 if (_doWorkAsyncMethod != null)
                 {
-                    await (Task) _doWorkAsyncMethod.Invoke(asyncWorker, new object[] {workerContext});
+                    await (Task) (_doWorkAsyncMethod.Invoke(asyncWorker, new object[] {workerContext})!);
                 }
 
                 break;
diff --git a/framework/src/Volo.Abp.BackgroundWorkers/Volo.Abp.BackgroundWorkers.csproj b/framework/src/Volo.Abp.BackgroundWorkers/Volo.Abp.BackgroundWorkers.csproj
index f01a73d7a1..48e4b5fdf7 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers/Volo.Abp.BackgroundWorkers.csproj
+++ b/framework/src/Volo.Abp.BackgroundWorkers/Volo.Abp.BackgroundWorkers.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.BackgroundWorkers</AssemblyName>
     <PackageId>Volo.Abp.BackgroundWorkers</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerBase.cs b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerBase.cs
index dc32981d58..91bc360f72 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerBase.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerBase.cs
@@ -14,13 +14,13 @@ public abstract class BackgroundWorkerBase : IBackgroundWorker
 {
     //TODO: Add UOW, Localization and other useful properties..?
 
-    public IAbpLazyServiceProvider LazyServiceProvider { get; set; }
+    public IAbpLazyServiceProvider LazyServiceProvider { get; set; } = default!;
 
-    public IServiceProvider ServiceProvider { get; set; }
+    public IServiceProvider ServiceProvider { get; set; } = default!;
 
     protected ILoggerFactory LoggerFactory => LazyServiceProvider.LazyGetRequiredService<ILoggerFactory>();
 
-    protected ILogger Logger => LazyServiceProvider.LazyGetService<ILogger>(provider => LoggerFactory?.CreateLogger(GetType().FullName) ?? NullLogger.Instance);
+    protected ILogger Logger => LazyServiceProvider.LazyGetService<ILogger>(provider => LoggerFactory?.CreateLogger(GetType().FullName!) ?? NullLogger.Instance);
 
     protected CancellationTokenSource StoppingTokenSource { get; }
     protected CancellationToken StoppingToken { get; }
@@ -47,6 +47,6 @@ public abstract class BackgroundWorkerBase : IBackgroundWorker
 
     public override string ToString()
     {
-        return GetType().FullName;
+        return GetType().FullName!;
     }
 }
diff --git a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/PeriodicBackgroundWorkerBase.cs b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/PeriodicBackgroundWorkerBase.cs
index 393a4766cf..9d78d9237d 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/PeriodicBackgroundWorkerBase.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/PeriodicBackgroundWorkerBase.cs
@@ -37,7 +37,7 @@ public abstract class PeriodicBackgroundWorkerBase : BackgroundWorkerBase
         await base.StopAsync(cancellationToken);
     }
 
-    private void Timer_Elapsed(object sender, System.EventArgs e)
+    private void Timer_Elapsed(object? sender, System.EventArgs e)
     {
         using (var scope = ServiceScopeFactory.CreateScope())
         {
diff --git a/framework/src/Volo.Abp.HangFire/Volo.Abp.HangFire.csproj b/framework/src/Volo.Abp.HangFire/Volo.Abp.HangFire.csproj
index dfd64e0b1a..07e299f859 100644
--- a/framework/src/Volo.Abp.HangFire/Volo.Abp.HangFire.csproj
+++ b/framework/src/Volo.Abp.HangFire/Volo.Abp.HangFire.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.HangFire</AssemblyName>
     <PackageId>Volo.Abp.HangFire</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireAuthorizationFilter.cs b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireAuthorizationFilter.cs
index 9b6a6941ae..bd65b22dba 100644
--- a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireAuthorizationFilter.cs
+++ b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireAuthorizationFilter.cs
@@ -10,9 +10,9 @@ namespace Volo.Abp.Hangfire;
 public class AbpHangfireAuthorizationFilter : IDashboardAsyncAuthorizationFilter
 {
     private readonly bool _enableTenant;
-    private readonly string _requiredPermissionName;
+    private readonly string? _requiredPermissionName;
 
-    public AbpHangfireAuthorizationFilter(bool enableTenant = false, string requiredPermissionName = null)
+    public AbpHangfireAuthorizationFilter(bool enableTenant = false, string? requiredPermissionName = null)
     {
         _enableTenant = requiredPermissionName.IsNullOrWhiteSpace() ? enableTenant : true;
         _requiredPermissionName = requiredPermissionName;
@@ -30,7 +30,7 @@ public class AbpHangfireAuthorizationFilter : IDashboardAsyncAuthorizationFilter
             return true;
         }
 
-        return await IsPermissionGrantedAsync(context, _requiredPermissionName);
+        return await IsPermissionGrantedAsync(context, _requiredPermissionName!);
     }
 
     private static bool IsLoggedIn(DashboardContext context, bool enableTenant)
diff --git a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireBackgroundJobServer.cs b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireBackgroundJobServer.cs
index e24042c87b..5f3e3deb96 100644
--- a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireBackgroundJobServer.cs
+++ b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireBackgroundJobServer.cs
@@ -4,9 +4,9 @@ namespace Volo.Abp.Hangfire;
 
 public class AbpHangfireBackgroundJobServer
 {
-    public BackgroundJobServer HangfireJobServer { get; }
+    public BackgroundJobServer? HangfireJobServer { get; }
 
-    public AbpHangfireBackgroundJobServer(BackgroundJobServer hangfireJobServer)
+    public AbpHangfireBackgroundJobServer(BackgroundJobServer? hangfireJobServer)
     {
         HangfireJobServer = hangfireJobServer;
     }
diff --git a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireModule.cs b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireModule.cs
index 13f36751aa..6c34b86904 100644
--- a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireModule.cs
+++ b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireModule.cs
@@ -9,7 +9,7 @@ namespace Volo.Abp.Hangfire;
 [DependsOn(typeof(AbpAuthorizationAbstractionsModule))]
 public class AbpHangfireModule : AbpModule
 {
-    private AbpHangfireBackgroundJobServer _backgroundJobServer;
+    private AbpHangfireBackgroundJobServer? _backgroundJobServer;
 
     public override void ConfigureServices(ServiceConfigurationContext context)
     {
diff --git a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireOptions.cs b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireOptions.cs
index 43c5554d55..98c45348c7 100644
--- a/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireOptions.cs
+++ b/framework/src/Volo.Abp.HangFire/Volo/Abp/Hangfire/AbpHangfireOptions.cs
@@ -12,21 +12,18 @@ namespace Volo.Abp.Hangfire;
 
 public class AbpHangfireOptions
 {
-    [CanBeNull]
-    public BackgroundJobServerOptions ServerOptions { get; set; }
+    public BackgroundJobServerOptions? ServerOptions { get; set; }
 
-    [CanBeNull]
-    public IEnumerable<IBackgroundProcess> AdditionalProcesses { get; set; }
+    public IEnumerable<IBackgroundProcess>? AdditionalProcesses { get; set; }
 
-    [CanBeNull]
-    public JobStorage Storage { get; set; }
+    public JobStorage? Storage { get; set; }
 
     [NotNull]
-    public Func<IServiceProvider, BackgroundJobServer> BackgroundJobServerFactory {
+    public Func<IServiceProvider, BackgroundJobServer?> BackgroundJobServerFactory {
         get => _backgroundJobServerFactory;
         set => _backgroundJobServerFactory = Check.NotNull(value, nameof(value));
     }
-    private Func<IServiceProvider, BackgroundJobServer> _backgroundJobServerFactory;
+    private Func<IServiceProvider, BackgroundJobServer?> _backgroundJobServerFactory;
 
     public AbpHangfireOptions()
     {
diff --git a/framework/src/Volo.Abp.Quartz/Volo.Abp.Quartz.csproj b/framework/src/Volo.Abp.Quartz/Volo.Abp.Quartz.csproj
index 71c3dd4caf..0f72827fcb 100644
--- a/framework/src/Volo.Abp.Quartz/Volo.Abp.Quartz.csproj
+++ b/framework/src/Volo.Abp.Quartz/Volo.Abp.Quartz.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.Quartz</AssemblyName>
     <PackageId>Volo.Abp.Quartz</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzModule.cs b/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzModule.cs
index 10e09444c5..1f0bfb0ff6 100644
--- a/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzModule.cs
+++ b/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzModule.cs
@@ -10,7 +10,7 @@ namespace Volo.Abp.Quartz;
 
 public class AbpQuartzModule : AbpModule
 {
-    private IScheduler _scheduler;
+    private IScheduler _scheduler = default!;
 
     public override void ConfigureServices(ServiceConfigurationContext context)
     {
diff --git a/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzOptions.cs b/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzOptions.cs
index 8f61f3c91d..5f6bb97fd1 100644
--- a/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzOptions.cs
+++ b/framework/src/Volo.Abp.Quartz/Volo/Abp/Quartz/AbpQuartzOptions.cs
@@ -13,7 +13,7 @@ public class AbpQuartzOptions
     /// </summary>
     public NameValueCollection Properties { get; set; }
 
-    public Action<IServiceCollectionQuartzConfigurator> Configurator { get; set; }
+    public Action<IServiceCollectionQuartzConfigurator>? Configurator { get; set; }
 
     /// <summary>
     /// How long Quartz should wait before starting. Default: 0.
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo.Abp.RabbitMQ.csproj b/framework/src/Volo.Abp.RabbitMQ/Volo.Abp.RabbitMQ.csproj
index eed4f273fd..0895e07153 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo.Abp.RabbitMQ.csproj
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo.Abp.RabbitMQ.csproj
@@ -5,6 +5,8 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <WarningsAsErrors>Nullable</WarningsAsErrors>
     <AssemblyName>Volo.Abp.RabbitMQ</AssemblyName>
     <PackageId>Volo.Abp.RabbitMQ</PackageId>
     <AssetTargetFallback>$(AssetTargetFallback);portable-net45+win8+wp8+wpa81;</AssetTargetFallback>
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ChannelPool.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ChannelPool.cs
index 541bc9b852..d795342c1d 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ChannelPool.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ChannelPool.cs
@@ -29,7 +29,7 @@ public class ChannelPool : IChannelPool, ISingletonDependency
         Logger = NullLogger<ChannelPool>.Instance;
     }
 
-    public virtual IChannelAccessor Acquire(string channelName = null, string connectionName = null)
+    public virtual IChannelAccessor Acquire(string? channelName = null, string? connectionName = null)
     {
         CheckDisposed();
 
@@ -49,7 +49,7 @@ public class ChannelPool : IChannelPool, ISingletonDependency
         );
     }
 
-    protected virtual IModel CreateChannel(string channelName, string connectionName)
+    protected virtual IModel CreateChannel(string channelName, string? connectionName)
     {
         return ConnectionPool
             .Get(connectionName)
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ConnectionPool.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ConnectionPool.cs
index 3a228f5d10..8c046ffffd 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ConnectionPool.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/ConnectionPool.cs
@@ -21,7 +21,7 @@ public class ConnectionPool : IConnectionPool, ISingletonDependency
         Connections = new ConcurrentDictionary<string, Lazy<IConnection>>();
     }
 
-    public virtual IConnection Get(string connectionName = null)
+    public virtual IConnection Get(string? connectionName = null)
     {
         connectionName ??= RabbitMqConnections.DefaultConnectionName;
 
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IChannelPool.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IChannelPool.cs
index 75b6e77580..2ba6259fec 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IChannelPool.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IChannelPool.cs
@@ -4,5 +4,5 @@ namespace Volo.Abp.RabbitMQ;
 
 public interface IChannelPool : IDisposable
 {
-    IChannelAccessor Acquire(string channelName = null, string connectionName = null);
+    IChannelAccessor Acquire(string? channelName = null, string? connectionName = null);
 }
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IConnectionPool.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IConnectionPool.cs
index 09b8b407f9..dc97476c84 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IConnectionPool.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IConnectionPool.cs
@@ -5,5 +5,5 @@ namespace Volo.Abp.RabbitMQ;
 
 public interface IConnectionPool : IDisposable
 {
-    IConnection Get(string connectionName = null);
+    IConnection Get(string? connectionName = null);
 }
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IRabbitMqMessageConsumerFactory.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IRabbitMqMessageConsumerFactory.cs
index 31770e641b..33d0e5d07e 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IRabbitMqMessageConsumerFactory.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/IRabbitMqMessageConsumerFactory.cs
@@ -14,6 +14,6 @@ public interface IRabbitMqMessageConsumerFactory
     IRabbitMqMessageConsumer Create(
         ExchangeDeclareConfiguration exchange,
         QueueDeclareConfiguration queue,
-        string connectionName = null
+        string? connectionName = null
     );
 }
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumer.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumer.cs
index 5c45b6aefc..1d94122008 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumer.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumer.cs
@@ -23,15 +23,15 @@ public class RabbitMqMessageConsumer : IRabbitMqMessageConsumer, ITransientDepen
 
     protected AbpAsyncTimer Timer { get; }
 
-    protected ExchangeDeclareConfiguration Exchange { get; private set; }
+    protected ExchangeDeclareConfiguration Exchange { get; private set; } = default!;
 
-    protected QueueDeclareConfiguration Queue { get; private set; }
+    protected QueueDeclareConfiguration Queue { get; private set; } = default!;
 
-    protected string ConnectionName { get; private set; }
+    protected string? ConnectionName { get; private set; }
 
     protected ConcurrentBag<Func<IModel, BasicDeliverEventArgs, Task>> Callbacks { get; }
 
-    protected IModel Channel { get; private set; }
+    protected IModel? Channel { get; private set; }
 
     protected ConcurrentQueue<QueueBindCommand> QueueBindCommands { get; }
 
@@ -58,7 +58,7 @@ public class RabbitMqMessageConsumer : IRabbitMqMessageConsumer, ITransientDepen
     public void Initialize(
         [NotNull] ExchangeDeclareConfiguration exchange,
         [NotNull] QueueDeclareConfiguration queue,
-        string connectionName = null)
+        string? connectionName = null)
     {
         Exchange = Check.NotNull(exchange, nameof(exchange));
         Queue = Check.NotNull(queue, nameof(queue));
@@ -192,16 +192,16 @@ public class RabbitMqMessageConsumer : IRabbitMqMessageConsumer, ITransientDepen
         {
             foreach (var callback in Callbacks)
             {
-                await callback(Channel, basicDeliverEventArgs);
+                await callback(Channel!, basicDeliverEventArgs);
             }
 
-            Channel.BasicAck(basicDeliverEventArgs.DeliveryTag, multiple: false);
+            Channel?.BasicAck(basicDeliverEventArgs.DeliveryTag, multiple: false);
         }
         catch (Exception ex)
         {
             try
             {
-                Channel.BasicNack(
+                Channel?.BasicNack(
                     basicDeliverEventArgs.DeliveryTag,
                     multiple: false,
                     requeue: true
diff --git a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumerFactory.cs b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumerFactory.cs
index 1b3f1714e8..8dcdf7101f 100644
--- a/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumerFactory.cs
+++ b/framework/src/Volo.Abp.RabbitMQ/Volo/Abp/RabbitMQ/RabbitMqMessageConsumerFactory.cs
@@ -16,7 +16,7 @@ public class RabbitMqMessageConsumerFactory : IRabbitMqMessageConsumerFactory, I
     public IRabbitMqMessageConsumer Create(
         ExchangeDeclareConfiguration exchange,
         QueueDeclareConfiguration queue,
-        string connectionName = null)
+        string? connectionName = null)
     {
         var consumer = ServiceScope.ServiceProvider.GetRequiredService<RabbitMqMessageConsumer>();
         consumer.Initialize(exchange, queue, connectionName);