A task was canceled with IHttpClientFactory

Question

I made a post method with IHttpClientFactory with .net 6 like this:

public object Post(string URL,object PostObject,  Type ResponseObjectType)  
        {  
            try  
            {  
                var client = clientFactory.CreateClient();                  
                client.Timeout = TimeSpan.FromSeconds(3);  
                var options = new JsonSerializerOptions();  
                options.Encoder = System.Text.Encodings.Web.JavaScriptEncoder.Create(UnicodeRanges.All);  
                string JsonContent = JsonSerializer.Serialize(PostObject, PostObject.GetType(), options);                  
                var response = client.PostAsync(URL, new StringContent(JsonContent, Encoding.UTF8, "application/json")).Result;  
                if (response.StatusCode == System.Net.HttpStatusCode.NotFound || response.Content == null)  
                {  
                    client.Dispose();  
                    return null;  
                }  
                else  
                {  
                    object Result;  
                    if (ResponseObjectType == typeof(string))  
                    {  
                        Result = response.Content.ReadAsStringAsync().Result;  
                    }  
                    else  
                    {  
                        Result = response.Content.ReadFromJsonAsync(ResponseObjectType, options).Result;  
                    }  
                    client.Dispose();  
                    return Result;  
                }  
            }  
            catch (Exception ex)  
            {  
                LogException(ex, URL);  
                return null;  
            }  
        }

Sometimes (not always) the code runs with the error above:

System.Threading.Tasks.TaskCanceledException: A task was canceled.
at System.Threading.Tasks.Task.GetExceptions(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification) at SIComponent.Global.Post(String URL, Object PostObject, Type ResponseObjectType) in C:\Project\Sample\SIComponent\Global.cs:line 317 at SIComponent.Middleware.BlackListMiddleware.Invoke(HttpContext context) in C:\Project\Sample\SIComponent\Middleware\BlackListMiddleware.cs:line 135 at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at SIComponent.Middleware.BlackListMiddleware.Invoke(HttpContext context) at SIComponent.Middleware.RedirectUpperURLMiddleware.InvokeAsync(HttpContext context) in C:\Project\Sample\SIComponent\Middleware\RedirectUpperURLMiddleware.cs:line 31 at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at SIComponent.Middleware.RedirectUpperURLMiddleware.InvokeAsync(HttpContext context) at SIComponent.Middleware.ExceptionMiddleware.Invoke(HttpContext context) in C:\Project\Sample\SIComponent\Middleware\ExceptionMiddleware.cs:line 25 at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at SIComponent.Middleware.ExceptionMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext) at Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Localization.RequestLocalizationMiddleware.Invoke(HttpContext context) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Microsoft.AspNetCore.Localization.RequestLocalizationMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.TryServeStaticFile(HttpContext context, String contentType, PathString subPath) at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Builder.UseWhenExtensions.<>c__DisplayClass0_1.b__1(HttpContext context) at Microsoft.AspNetCore.Rewrite.RewriteMiddleware.Invoke(HttpContext context) at Marvin.Cache.Headers.HttpCacheHeadersMiddleware.HandleResponse(HttpContext httpContext) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Marvin.Cache.Headers.HttpCacheHeadersMiddleware.HandleResponse(HttpContext httpContext) at Marvin.Cache.Headers.HttpCacheHeadersMiddleware.Invoke(HttpContext httpContext, IValidatorValueInvalidator validatorValueInvalidator) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine) at Marvin.Cache.Headers.HttpCacheHeadersMiddleware.Invoke(HttpContext httpContext, IValidatorValueInvalidator validatorValueInvalidator) at lambda_method1(Closure , Object , HttpContext , IServiceProvider ) at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.<>c__DisplayClass5_1.b__2(HttpContext context) at Microsoft.AspNetCore.Cors.Infrastructure.CorsMiddleware.Invoke(HttpContext context, ICorsPolicyProvider corsPolicyProvider) at lambda_method2(Closure , Object , HttpContext , IServiceProvider ) at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.<>c__DisplayClass5_1.b__2(HttpContext context) at Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Hosting.HostingApplication.ProcessRequestAsync(Context context) at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContextOfT1.ProcessRequestAsync()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.StartTStateMachine
at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContextOfT`1.ProcessRequestAsync()
at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContext.HandleRequest()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.StartTStateMachine
at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContext.HandleRequest()
at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContext.Execute()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()
at System.Threading.Thread.StartCallback()
--- End of stack trace from previous location ---

In addition, every time it throws error when posting the same URL at the code:
var response = client.PostAsync(URL, new StringContent(JsonContent, Encoding.UTF8, "application/json")).Result;

What's wrong with this? Is it the problem with the remote server or my code? Thank you.

Answer

you need to use async and await, change the following code and try

public async object Post(string URL,object PostObject,  Type ResponseObjectType)  
 {  
					     
		\ other code  
		    
		 var response = await client.PostAsync(URL, new StringContent(JsonContent, Encoding.UTF8, "application/json")).Result;  
		   
//other code  
  
 }

A task was canceled with IHttpClientFactory

1 answer