2

I am using VS 2012 and set the target framework 4.0.

public async Task<HttpResponseMessage> GetResponse(Uri url)             
{                 
    this.httpClient.DefaultRequestHeaders.Accept.Clear();                 
    HttpResponseMessage response = await this.httpClient.GetAsync(url);                 
    response.EnsureSuccessStatusCode();             
}

Error:

System.NullReferenceException was unhandled
HResult=-2147467261
Message=Object reference not set to an instance of an object.
Source=Microsoft.CompilerServices.AsyncTargetingPack.Net4
StackTrace:
Server stack trace: at System.Web.ThreadContext.AssociateWithCurrentThread(Boolean  setImpersonationContext) at System.Web.HttpApplication.OnThreadEnterPrivate(Boolean setImpersonationContext) at System.Web.LegacyAspNetSynchronizationContext.CallCallbackPossiblyUnderLock(SendOrPostCallback callback, Object state) at System.Web.LegacyAspNetSynchronizationContext.CallCallback(SendOrPostCallback callback, Object state) at System.Web.LegacyAspNetSynchronizationContext.Post(SendOrPostCallback callback, Object state) at System.Runtime.CompilerServices.TaskAwaiter.<>c__DisplayClassa.<OnCompletedInternal>b__0(Task param0)
        Exception rethrown at [0]: at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>b__1(Object state)
           at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
           at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
           at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
           at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
           at System.Threading.ThreadPoolWorkQueue.Dispatch()
           at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
      InnerException: 
    -------------------------------------------------

I have installed "Microsoft.CompilerServices.AsyncTargetingPack" from NuGet, but still getting this error. Any suggestion.

Improve this question
3
  • Have you tried using Microsoft.Bcl.Async instead of Microsoft.CompilerServices.AsyncTargetingPack? Commented Feb 19, 2013 at 15:19
  • yes, i used Microsoft.Bcl.Async link as well but still getting same error. Commented Feb 20, 2013 at 6:37
  • Take a look at my question. May be it will help you. Commented Mar 15, 2013 at 17:49
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