尝试在DocumentDB中创建文档时获取"任务已取消"

Question

当我尝试使用以下代码在我的DocumentDB数据库中创建文档时,代码挂起我调用CreateDocumentAsync()的地方,并最终给我"任务被取消"错误.

知道为什么吗？

public static async Task<Employee> CreateEmployee(Employee emp)
{
   try
   {
      using (client = new DocumentClient(new Uri(endPointUrl), authorizationKey))
      {
         //Get the database
         var database = await GetDatabaseAsync();

         //Get the Document Collection
         var collection = await GetCollectionAsync(database.SelfLink, "Employees");

         await client.CreateDocumentAsync(collection.SelfLink, emp);

         // Do something else with employee
      }
   }
   catch
   {
      // Handle error
   }

   return emp;
}

PS为简洁起见,我没有包含GetDatabaseAsync()和GetCollectionsAsync()部分的代码.请注意,员工文档是在我的数据库中创建的.因此,此代码清楚地连接到DocumentDB数据库,查找集合并创建文档.

只是不确定为什么它会挂起并最终返回错误.

*****更新******

这是错误详细信息:任务已取消.

描述:执行当前Web请求期间发生未处理的异常.请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息.

异常详细信息:System.Threading.Tasks.TaskCanceledException:任务已取消.来源错误:

HttpResponseMessage response = await client.PostAsJsonAsync("api/hr/register", employee);

堆栈跟踪:

[TaskCanceledException: A task was canceled.]
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +10915395
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +52
   System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() +24
   ConsumerWebApi.Controllers.<Index>d__0.MoveNext() in c:\Users\Sam\Documents\Visual Studio 2013\Projects\ConsumerWebApi\ConsumerWebApi\Controllers\HomeController.cs:36
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +22
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +10915367
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +52
   System.Runtime.CompilerServices.TaskAwaiter.GetResult() +21
   System.Threading.Tasks.TaskHelpersExtensions.ThrowIfFaulted(Task task) +61
   System.Web.Mvc.Async.TaskAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult) +114
   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeAsynchronousActionMethod>b__36(IAsyncResult asyncResult) +66
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +47
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +135
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +102
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +49
   System.Web.Mvc.Async.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() +117
   System.Web.Mvc.Async.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +323
   System.Web.Mvc.Async.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult) +44
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +47
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +135
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +102
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +50
   System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +72
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +185
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +42
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +132
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +56
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +40
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +34
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +70
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +138
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +59
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +40
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +44
   System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +39
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +62
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +138
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +59
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +40
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +39
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +39
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +39
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +70
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +138
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +59
   System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +40
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +40
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +38
   System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +129

Answer 1

问题是由于未正确调用异步调用引起的.我正在调用异步方法,即CreateDocumentAsync()错误.

我发布了一个关于异步编程的单独问题,我得到的答案帮助我解决了这个问题.这是帖子: 想了解异步

Answer 2

我使用其中一个DocumentClient异步函数抛出了类似的错误。我await对每个呼叫都正确使用，但后来我发现这是由代理服务器 干扰流量引起的。因此，对于那些在公司网络内部工作的人来说，请考虑检查这一点。