Silverlight 5中postAsync上的可移植Microsoft.Net.Http對象引用錯誤

Question

代碼很簡單：

var http = new HttpClient();
var uri = new Uri(Application.Current.Host.Source, "/api/query");
var postContext = new StringContent("test");
var response = await http.PostAsync(uri, postContext);

錯誤是：對象空引用

at System.Net.Http.DelegatingStream.get_CanSeek()
at System.Net.Http.StreamContent..ctor(Stream content, Int32 bufferSize)
at System.Net.Http.StreamContent..ctor(Stream content)
at System.Net.Http.HttpClientHandler.CreateResponseMessage(HttpWebResponse webResponse, HttpRequestMessage request)
at System.Net.Http.HttpClientHandler.TryGetExceptionResponse(WebException webException, HttpRequestMessage requestMessage, HttpResponseMessage& httpResponseMessage)
at System.Net.Http.HttpClientHandler.HandleAsyncException(RequestState state, Exception e)
at System.Net.Http.HttpClientHandler.GetResponseCallback(IAsyncResult ar)
at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass19.<InvokeGetResponseCallback>b__17(Object state2)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
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()

GetAsync效果很好。 但是PostAsync崩潰了。

Answer 1

請求失敗（請注意堆棧中的HandleAsyncException）時，這是HttpWebRequest的Silverlight瀏覽器實現中的錯誤。 我們已經在較新版本的Microsoft.Net.Http中提供了解決方法，該版本應該很快就會發布。

現在，您可以嘗試在SL中使用不返回空流的客戶端堆棧。 http://msdn.microsoft.com/zh-CN/library/dd920295(v=VS.95).aspx