c# - 等待 PostAsJsonAsync 时抛出 AggregateException

Question

在等待 API 发布完成时抛出 AggregateException 我该如何解决这个问题？

我的API调用类似这样

using (var httpClient = new HttpClient())
{
    httpClient.BaseAddress = new Uri(workflowUrl);
    var task = httpClient.PostAsJsonAsync("api/apiname/execute/", executeModel)
                             .ContinueWith(x => x.Result.Content.ReadAsAsync<bool>().Result);

    Task continuation = task.ContinueWith(x =>
    {
        bool response = x.Result;
    });
    continuation.Wait(); 

}

我在等待 POST 完成时收到下面给出的异常。

  System.AggregateException was caught
  Message=One or more errors occurred.
  Source=mscorlib
  StackTrace:
       at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
       at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
       at System.Threading.Tasks.Task.Wait()
       at 
  InnerException: System.AggregateException
       Message=One or more errors occurred.
       Source=mscorlib
       StackTrace:
            at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
            at System.Threading.Tasks.Task`1.get_Result()
            at 
            at System.Threading.Tasks.Task`1.<>c__DisplayClass17.<ContinueWith>b__16(Object obj)
            at System.Threading.Tasks.Task.InnerInvoke()
            at System.Threading.Tasks.Task.Execute()
       InnerException: System.AggregateException
            Message=One or more errors occurred.
            Source=mscorlib
            StackTrace:
                 at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
                 at System.Threading.Tasks.Task`1.get_Result()
                 at WebUI.ListController.<ListRepeater_ItemCommand>b__f(Task`1 x) in PostAsJsonAsync:line 741
                 at System.Threading.Tasks.Task`1.<>c__DisplayClass1a`1.<ContinueWith>b__19()
                 at System.Threading.Tasks.Task`1.InvokeFuture(Object futureAsObj)
                 at System.Threading.Tasks.Task.InnerInvoke()
                 at System.Threading.Tasks.Task.Execute()
            InnerException: System.Threading.Tasks.TaskCanceledException
                 Message=A task was canceled.
                 InnerException:

Answer 1

您要发布大量数据吗？有一次我遇到了类似的问题。我相信潜在的问题是由于带宽问题偶尔超时。我尝试获取任务并手动等待它，然后检查 .IsFaulted 和 .IsCancelled 但 .Result 抛出 AggregateException/任务取消异常。

也许你应该尝试增加HttpClient.Timeout默认为 100 秒的属性？