Introduction

It's a problem project for httpClientFactory with Middleware .

Steps

1.Open the Project with sln file which in 5.7.0/aspnet-core/ABPTest.sln.

2.F5 and deubugger the project.

3.Set the breakpoint in TestClientMiddelware.cs file at line 12.

4.In the browser or postman input the url:http://localhost:21021/HOME/testhttpclient ,and visit it.

5.You will see the first visit,the project can return correct response,But when the second visit the same url the project will throw an exception with Cannot access a disposed object.

the exception detail is

INFO  2020-08-15 20:50:43,086 [12   ] c.Infrastructure.ControllerActionInvoker - Executed action ABPTest.Web.Host.Controllers.HomeController.TestHttpClient (ABPTest.Web.Host) in 2058.5657ms
INFO  2020-08-15 20:50:43,089 [12   ] ft.AspNetCore.Routing.EndpointMiddleware - Executed endpoint 'ABPTest.Web.Host.Controllers.HomeController.TestHttpClient (ABPTest.Web.Host)'
INFO  2020-08-15 20:50:43,093 [12   ] Microsoft.AspNetCore.Hosting.Diagnostics - Request finished in 2079.4088ms 500 application/json; charset=utf-8
INFO  2020-08-15 20:51:01,396 [17   ] Microsoft.AspNetCore.Hosting.Diagnostics - Request starting HTTP/1.1 GET http://localhost:21021/HOME/testhttpclient  
INFO  2020-08-15 20:51:01,400 [17   ] ft.AspNetCore.Routing.EndpointMiddleware - Executing endpoint 'ABPTest.Web.Host.Controllers.HomeController.TestHttpClient (ABPTest.Web.Host)'
INFO  2020-08-15 20:51:01,404 [17   ] c.Infrastructure.ControllerActionInvoker - Route matched with {action = "TestHttpClient", controller = "Home", area = ""}. Executing controller action with signature System.Threading.Tasks.Task`1[System.String] TestHttpClient() on controller ABPTest.Web.Host.Controllers.HomeController (ABPTest.Web.Host).
INFO  2020-08-15 20:51:01,430 [17   ] c.Infrastructure.ControllerActionInvoker - Executing action method ABPTest.Web.Host.Controllers.HomeController.TestHttpClient (ABPTest.Web.Host) - Validation state: Valid
INFO  2020-08-15 20:51:01,433 [17   ] ttp.HttpClient.TestClient.LogicalHandler - Start processing HTTP request GET https://www.baidu.com/
ERROR 2020-08-15 20:51:03,026 [15   ] Mvc.ExceptionHandling.AbpExceptionFilter - Cannot access a disposed object.
Object name: 'ABPTest.Web.Host.TestClientMiddelware'.
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'ABPTest.Web.Host.TestClientMiddelware'.
   at System.Net.Http.DelegatingHandler.CheckDisposed()
   at System.Net.Http.DelegatingHandler.SetOperationStarted()
   at System.Net.Http.DelegatingHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at ABPTest.Web.Host.TestClientMiddelware.<>n__0(HttpRequestMessage request, CancellationToken cancellationToken)
   at ABPTest.Web.Host.TestClientMiddelware.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) in D:\TestProgram\ABPTestGitHub\ABPHttpClientTest\5.7.0\aspnet-core\src\ABPTest.Web.Host\TestClientMiddelware.cs:line 12
   at Microsoft.Extensions.Http.Logging.LoggingScopeHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.FinishSendAsyncUnbuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
   at System.Net.Http.HttpClient.GetStringAsyncCore(Task`1 getTask)
   at ABPTest.Web.Host.TestClient.GetTest(String url) in D:\TestProgram\ABPTestGitHub\ABPHttpClientTest\5.7.0\aspnet-core\src\ABPTest.Web.Host\TestClient.cs:line 33
   at ABPTest.Web.Host.Controllers.HomeController.TestHttpClient() in D:\TestProgram\ABPTestGitHub\ABPHttpClientTest\5.7.0\aspnet-core\src\ABPTest.Web.Host\Controllers\HomeController.cs:line 23
   at lambda_method(Closure , Object )
   at Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable.Awaiter.GetResult()
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Logged|12_1(ControllerActionInvoker invoker)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextExceptionFilterAsync>g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
INFO  2020-08-15 20:51:03,031 [15   ] .Mvc.Infrastructure.ObjectResultExecutor - Executing ObjectResult, writing value of type 'Abp.Web.Models.AjaxResponse'.
INFO  2020-08-15 20:51:03,034 [15   ] c.Infrastructure.ControllerActionInvoker - Executed action ABPTest.Web.Host.Controllers.HomeController.TestHttpClient (ABPTest.Web.Host) in 1627.9669ms
INFO  2020-08-15 20:51:03,037 [15   ] ft.AspNetCore.Routing.EndpointMiddleware - Executed endpoint 'ABPTest.Web.Host.Controllers.HomeController.TestHttpClient (ABPTest.Web.Host)'
INFO  2020-08-15 20:51:03,039 [15   ] Microsoft.AspNetCore.Hosting.Diagnostics - Request finished in 1642.5265ms 500 application/json; charset=utf-8

who can help me ?