Task.Wait（）不包括任何链接（ContinueWith）任务

Question

如果你有

Private Shared Sub msg(Optional message As String = "") 
    Debug.WriteLine(Threading.Thread.CurrentThread.ManagedThreadId & " " & message) 
End Sub 
<TestMethod()> 
Public Sub TestMethod1() 
    Dim cancel As New Threading.CancellationTokenSource 
    msg("starting") 
    Dim start As DateTime = DateTime.Now 
    Dim task As New Task(Sub() 
          msg("in thread") 
          Do Until Now.Subtract(start).TotalMilliseconds > 2000 
           Threading.Thread.Sleep(500) 
           msg("loop") 
           cancel.Token.ThrowIfCancellationRequested() 
          Loop 
         End Sub, cancel.Token, TaskCreationOptions.LongRunning) 
    task.ContinueWith(Sub(result As task) 
          msg("Continue task running") 
          Debug.WriteLine(result.Status.ToString & If(result.Exception Is Nothing, ", no exception", ", exception occurred " & result.Exception.GetType.Name)) 
          Do Until Now.Subtract(start).TotalMilliseconds > 10000 
           cancel.Token.ThrowIfCancellationRequested() 
           Threading.Thread.Sleep(500) 
           msg("innerloop") 
          Loop 
         End Sub) 
    task.Start() 
    Try 
     If Not task.Wait(4000, cancel.Token) Then 
      msg("wait expired, time to cancel)") 
      cancel.Cancel() 
     End If 
     task.Wait() 

    Catch ex As OperationCanceledException 
     msg("task was cancelled") 
    Finally 
     msg("finishing") 
    End Try 
End Sub 

的问题是，当我做task.Wait（4000，cancel.Token）这应该最终失败的ContinueWith任务不会在超时时间内完成。

似乎等待只适用于任务，并没有考虑到链，我怎么能等到“链”完成？

Answer 1

等待ContinueWith函数返回的任务。