有没有办法在新的异步DOTNET 4.5库设置在 Task.WhenAll 方法超时。我想取几个来源，并停止后说，5秒跳到了未完成的来源。

Is there a way in the new async dotnet 4.5 library to set a timeout on the Task.WhenAll method. I want to fetch several sources and stop after say 5 seconds and skip the sources that weren't finished.

推荐答案

您可以结合所产生的工作与 Task.Delay（）使用 Task.WhenAny（）：

You could combine the resulting Task with a Task.Delay() using Task.WhenAny():

await Task.WhenAny(Task.WhenAll(tasks), Task.Delay(timeout));

如果你想收获已完成的任务在发生超时：

If you want to harvest completed tasks in case of a timeout:

var completedResults =
  tasks
  .Where(t => t.Status == TaskStatus.RanToCompletion)
  .Select(t => t.Result)
  .ToList();