Add `IObjectToQueryString`.

framework/src/Volo.Abp.Core/Volo/Abp/Http/IObjectToQueryString.cs

@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+
+namespace Volo.Abp.Http
+{
+    public interface IObjectToQueryString<in TValue>
+    {
+        Task<string> ConvertAsync(TValue value);
+    }
+}

framework/src/Volo.Abp.Core/Volo/Abp/Reflection/ReflectionHelper.cs

@@ -134,7 +134,7 @@ namespace Volo.Abp.Reflection
             var currentType = objectType;
             var objectPath = currentType.FullName;
             var absolutePropertyPath = propertyPath;
-             if (objectPath != null && absolutePropertyPath.StartsWith(objectPath))
+            if (objectPath != null && absolutePropertyPath.StartsWith(objectPath))
             {
                 absolutePropertyPath = absolutePropertyPath.Replace(objectPath + ".", "");
             }
@@ -144,7 +144,10 @@ namespace Volo.Abp.Reflection
                 var property = currentType.GetProperty(propertyName);
                 if (property != null)
                 {
-                    value = property.GetValue(value, null);
+                    if (value != null)
+                    {
+                        value = property.GetValue(value, null);
+                    }
                     currentType = property.PropertyType;
                 }
                 else

framework/src/Volo.Abp.Http.Client/Volo/Abp/Http/Client/ClientProxying/ClientProxyBase.cs

@@ -156,9 +156,9 @@ namespace Volo.Abp.Http.Client.ClientProxying
             return new ApiVersionInfo(versionParam?.BindingSourceId, apiVersion);
         }
 
-        protected virtual Task<string> GetUrlWithParametersAsync(ClientProxyRequestContext requestContext, ApiVersionInfo apiVersion)
+        protected virtual async Task<string> GetUrlWithParametersAsync(ClientProxyRequestContext requestContext, ApiVersionInfo apiVersion)
         {
-            return Task.FromResult(ClientProxyUrlBuilder.GenerateUrlWithParameters(requestContext.Action, requestContext.Arguments, apiVersion));
+            return await ClientProxyUrlBuilder.GenerateUrlWithParametersAsync(requestContext.Action, requestContext.Arguments, apiVersion);
         }
 
         protected virtual Task<HttpContent> GetHttpContentAsync(ClientProxyRequestContext requestContext, ApiVersionInfo apiVersion)

framework/src/Volo.Abp.Http.Client/Volo/Abp/Http/Client/ClientProxying/ClientProxyUrlBuilder.cs

@@ -3,8 +3,11 @@ using System.Collections;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
+using System.Reflection;
 using System.Text;
+using System.Threading.Tasks;
 using JetBrains.Annotations;
+using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.DependencyInjection;
 using Volo.Abp.Http.Client.Proxying;
 using Volo.Abp.Http.Modeling;
@@ -15,7 +18,23 @@ namespace Volo.Abp.Http.Client.ClientProxying
 {
     public class ClientProxyUrlBuilder : ITransientDependency
     {
-        public string GenerateUrlWithParameters(ActionApiDescriptionModel action, IReadOnlyDictionary<string, object> methodArguments, ApiVersionInfo apiVersion)
+        protected static MethodInfo CallObjectToQueryStringAsyncMethod { get; }
+
+        static ClientProxyUrlBuilder()
+        {
+            CallObjectToQueryStringAsyncMethod = typeof(ClientProxyUrlBuilder)
+                .GetMethods(BindingFlags.NonPublic | BindingFlags.Instance)
+                .First(m => m.Name == nameof(ObjectToQueryStringAsync) && m.IsGenericMethodDefinition);
+        }
+
+        protected IServiceScopeFactory ServiceScopeFactory { get; }
+
+        public ClientProxyUrlBuilder(IServiceScopeFactory serviceScopeFactory)
+        {
+            ServiceScopeFactory = serviceScopeFactory;
+        }
+
+        public async Task<string> GenerateUrlWithParametersAsync(ActionApiDescriptionModel action, IReadOnlyDictionary<string, object> methodArguments, ApiVersionInfo apiVersion)
         {
             // The ASP.NET Core route value provider and query string value provider:
             //  Treat values as invariant culture.
@@ -24,14 +43,14 @@ namespace Volo.Abp.Http.Client.ClientProxying
             {
                 var urlBuilder = new StringBuilder(action.Url);
 
-                ReplacePathVariables(urlBuilder, action.Parameters, methodArguments, apiVersion);
-                AddQueryStringParameters(urlBuilder, action.Parameters, methodArguments, apiVersion);
+                await ReplacePathVariablesAsync(urlBuilder, action.Parameters, methodArguments, apiVersion);
+                await AddQueryStringParametersAsync(urlBuilder, action.Parameters, methodArguments, apiVersion);
 
                 return urlBuilder.ToString();
             }
         }
 
-        protected virtual void ReplacePathVariables(StringBuilder urlBuilder, IList<ParameterApiDescriptionModel> actionParameters, IReadOnlyDictionary<string, object> methodArguments, ApiVersionInfo apiVersion)
+        protected virtual Task ReplacePathVariablesAsync(StringBuilder urlBuilder, IList<ParameterApiDescriptionModel> actionParameters, IReadOnlyDictionary<string, object> methodArguments, ApiVersionInfo apiVersion)
         {
             var pathParameters = actionParameters
                 .Where(p => p.BindingSourceId == ParameterBindingSources.Path)
@@ -39,7 +58,7 @@ namespace Volo.Abp.Http.Client.ClientProxying
 
             if (!pathParameters.Any())
             {
-                return;
+                return Task.CompletedTask;
             }
 
             if (pathParameters.Any(p => p.Name == "apiVersion"))
@@ -71,9 +90,11 @@ namespace Volo.Abp.Http.Client.ClientProxying
                     urlBuilder = urlBuilder.Replace($"{{{pathParameter.Name}}}", value.ToString());
                 }
             }
+
+            return Task.CompletedTask;
         }
 
-        protected virtual void AddQueryStringParameters(StringBuilder urlBuilder, IList<ParameterApiDescriptionModel> actionParameters, IReadOnlyDictionary<string, object> methodArguments, ApiVersionInfo apiVersion)
+        protected virtual async Task AddQueryStringParametersAsync(StringBuilder urlBuilder, IList<ParameterApiDescriptionModel> actionParameters, IReadOnlyDictionary<string, object> methodArguments, ApiVersionInfo apiVersion)
         {
             var queryStringParameters = actionParameters
                 .Where(p => p.BindingSourceId.IsIn(ParameterBindingSources.ModelBinding, ParameterBindingSources.Query))
@@ -89,7 +110,26 @@ namespace Volo.Abp.Http.Client.ClientProxying
                     continue;
                 }
 
-                if (AddQueryStringParameter(urlBuilder, isFirstParam, queryStringParameter.Name, value))
+                using (var scope = ServiceScopeFactory.CreateScope())
+                {
+                    var objectToQuery = scope.ServiceProvider.GetService(typeof(IObjectToQueryString<>).MakeGenericType(value.GetType()));
+                    if (objectToQuery != null)
+                    {
+                        var queryString = await (Task<string>)CallObjectToQueryStringAsyncMethod
+                            .MakeGenericMethod(value.GetType())
+                            .Invoke(this, new object[] { value });
+
+                        if (!queryString.IsNullOrWhiteSpace())
+                        {
+                            urlBuilder.Append(isFirstParam ? "?" : "&");
+                            urlBuilder.Append(queryString);
+                            isFirstParam = false;
+                            continue;
+                        }
+                    }
+                }
+
+                if (await AddQueryStringParameterAsync(urlBuilder, isFirstParam, queryStringParameter.Name, value))
                 {
                     isFirstParam = false;
                 }
@@ -97,11 +137,24 @@ namespace Volo.Abp.Http.Client.ClientProxying
 
             if (apiVersion.ShouldSendInQueryString())
             {
-                AddQueryStringParameter(urlBuilder, isFirstParam, "api-version", apiVersion.Version);  //TODO: Constant!
+                await AddQueryStringParameterAsync(urlBuilder, isFirstParam, "api-version", apiVersion.Version);  //TODO: Constant!
+            }
+        }
+
+        protected virtual async Task<string> ObjectToQueryStringAsync<T>(T value)
+        {
+            using (var scope = ServiceScopeFactory.CreateScope())
+            {
+                var objectToQueryString = scope.ServiceProvider.GetService<IObjectToQueryString<T>>();
+                if (objectToQueryString != null)
+                {
+                    return await objectToQueryString.ConvertAsync(value);
+                }
             }
+            return null;
         }
 
-        protected virtual bool AddQueryStringParameter(
+        protected virtual async Task<bool> AddQueryStringParameterAsync(
             StringBuilder urlBuilder,
             bool isFirstParam,
             string name,
@@ -116,7 +169,7 @@ namespace Volo.Abp.Http.Client.ClientProxying
                     {
                         urlBuilder.Append(isFirstParam ? "?" : "&");
                     }
-                    urlBuilder.Append(name + $"[{index++}]=" + System.Net.WebUtility.UrlEncode(ConvertValueToString(item)) + "&");
+                    urlBuilder.Append(name + $"[{index++}]=" + System.Net.WebUtility.UrlEncode(await ConvertValueToStringAsync(item)) + "&");
                 }
 
                 if (index > 0)
@@ -130,18 +183,18 @@ namespace Volo.Abp.Http.Client.ClientProxying
             }
 
             urlBuilder.Append(isFirstParam ? "?" : "&");
-            urlBuilder.Append(name + "=" + System.Net.WebUtility.UrlEncode(ConvertValueToString(value)));
+            urlBuilder.Append(name + "=" + System.Net.WebUtility.UrlEncode(await ConvertValueToStringAsync(value)));
             return true;
         }
 
-        protected virtual string ConvertValueToString([CanBeNull] object value)
+        protected virtual Task<string> ConvertValueToStringAsync([CanBeNull] object value)
         {
             if (value is DateTime dateTimeValue)
             {
-                return dateTimeValue.ToUniversalTime().ToString("O");
+                return Task.FromResult(dateTimeValue.ToUniversalTime().ToString("O"));
             }
 
-            return value?.ToString();
+            return Task.FromResult(value?.ToString());
         }
     }
 }

framework/test/Volo.Abp.Http.Client.Tests/Volo/Abp/Http/DynamicProxying/PersonAppServiceClientProxy_Tests.cs

@@ -276,5 +276,32 @@ namespace Volo.Abp.Http.DynamicProxying
             });
             result.ShouldBe("123.rtf:File1:application/rtf:1-1.rtf123.rtf:File2:application/rtf2:1-2.rtf789.rtf:File3:application/rtf3:i-789.rtf");
         }
+
+        [Fact]
+        public async Task GetParamsFromQueryAsync()
+        {
+            var result = await _peopleAppService.GetParamsFromQueryAsync(new GetParamsFromQueryInput()
+            {
+                NameValues = new List<GetParamsFromQueryInputNameValue>()
+                {
+                    new GetParamsFromQueryInputNameValue()
+                    {
+                        Name = "name1",
+                        Value = "value1"
+                    },
+                    new GetParamsFromQueryInputNameValue()
+                    {
+                        Name = "name2",
+                        Value = "value2"
+                    }
+                },
+                NameValue = new GetParamsFromQueryInputNameValue()
+                {
+                    Name = "name3",
+                    Value = "value3"
+                }
+            });
+            result.ShouldBe("name1-value1:name2-value2:name3-value3");
+        }
     }
 }

framework/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/Dto/GetParamsFromQueryInput.cs

@@ -0,0 +1,44 @@
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+using Volo.Abp.DependencyInjection;
+using Volo.Abp.Http;
+
+namespace Volo.Abp.TestApp.Application.Dto
+{
+    public class GetParamsFromQueryInput
+    {
+        public List<GetParamsFromQueryInputNameValue> NameValues { get; set; }
+
+        public GetParamsFromQueryInputNameValue NameValue { get; set; }
+    }
+
+    public class GetParamsFromQueryInputNameValue
+    {
+        public string Name { get; set; }
+
+        public string Value { get; set; }
+    }
+
+    [ExposeServices(typeof(IObjectToQueryString<List<GetParamsFromQueryInputNameValue>>))]
+    public class TestInputToQueryString : IObjectToQueryString<List<GetParamsFromQueryInputNameValue>>, ITransientDependency
+    {
+        public Task<string> ConvertAsync(List<GetParamsFromQueryInputNameValue> values)
+        {
+            if (values.IsNullOrEmpty())
+            {
+                return null;
+            }
+
+            var sb = new StringBuilder();
+
+            for (var i = 0; i < values.Count; i++)
+            {
+                sb.Append($"NameValues[{i}].Name={values[i].Name}&NameValues[{i}].Value={values[i].Value}&");
+            }
+
+            sb.Remove(sb.Length - 1, 1);
+            return Task.FromResult(sb.ToString());
+        }
+    }
+}

framework/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/IPeopleAppService.cs

@@ -32,5 +32,6 @@ namespace Volo.Abp.TestApp.Application
 
         Task<string> CreateMultipleFileAsync(CreateMultipleFileInput input);
 
+        Task<string> GetParamsFromQueryAsync(GetParamsFromQueryInput input);
     }
 }

framework/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Application/PeopleAppService.cs

@@ -125,5 +125,13 @@ namespace Volo.Abp.TestApp.Application
 
             return str;
         }
+
+        public Task<string> GetParamsFromQueryAsync(GetParamsFromQueryInput input)
+        {
+            return Task.FromResult(input.NameValues?.FirstOrDefault()?.Name + "-" +
+                                   input.NameValues?.FirstOrDefault()?.Value + ":" +
+                                   input.NameValues?.LastOrDefault()?.Name + "-" + input.NameValues?.LastOrDefault()?.Value  + ":" +
+                                   input.NameValue?.Name + "-" + input.NameValue?.Value);
+        }
     }
 }