C# 带有CancellationToken的任务状态不为'；不变

我正在实现一个downloader类并使用Tasks，首先我创建了一个task并将CancellationToken传递给它，当我取消该task时，该task被取消，但该task的状态仍在运行，即使在调用ThrowifcCancellationRequested（）之后，状态仍然相同。如果我抛出ThrowIfCancellationRequested（），状态不应该被取消或出错吗

这是我的密码：

    public void Start()
    {
        //Start download
        Status = DownloadStatus.Running;
        CancellTS = new CancellationTokenSource();
        CancelT = CancellTS.Token;
        TaskStartDownload = Task.Run(() => { StartDownload(); }, CancelT);
    }

   private void StartDownload()
    {
        //Raise event download start
        if (OnDownloadStart != null)
            OnDownloadStart(this, new DownloadEventArgs(Id, 0, 0, 0, Controls, false));

        byte[] buffer = new byte[4096];
        long bytesToRead = Size;

        Timer.Start();
        while (!CancelT.IsCancellationRequested)
        {
            int currentBytesRead = Reader.Read(buffer, 0, buffer.Length);

            Speed = currentBytesRead == 0 ? 0 : ((float)BytesRead / 1024) / Timer.Elapsed.TotalSeconds;
            ProgressPercentage = ProgressPercentage + (currentBytesRead * 1.0 / Size) * 100;
            TimeRemaining = (int)(((double)(Size - BytesRead) / 1024) / Speed);

            if (currentBytesRead == 0)
            {
                Status = DownloadStatus.Completed;

                //Raise event download start
                if (OnDownloadComplete != null)
                    OnDownloadComplete(this, new DownloadEventArgs(Id, 100, 0, 0, Controls, false));

                break;
            }

            Writer.Write(buffer, 0, currentBytesRead);
            Writer.Flush();

            //Raise progress event
            this.OnDownloadProgress(this, new DownloadEventArgs(Id, Speed, ProgressPercentage, TimeRemaining, Controls, false));

            BytesRead += currentBytesRead;

            if (Status == DownloadStatus.Pause || Status == DownloadStatus.Cancel)
                break;
        }
        Timer.Stop();

        Reader.Close();
        Reader = null;
        Writer.Close();

        if (CancelT.IsCancellationRequested)
        {
            try
            {
                CancelT.ThrowIfCancellationRequested();
            }
            catch (Exception ex)
            {
                Status = DownloadStatus.Cancel;

                //Raise event download start
                if (OnDownloadCancel != null)
                    this.OnDownloadCancel(this, new DownloadEventArgs(Id, 0, 0, 0, Controls, true));

                File.Delete(FileNameWithPath);
            }
        }

        TaskPrepareDownload.Dispose();
        TaskStartDownload.Dispose();
    }

        public void Cancel()
    {
        if (TaskStartDownload == null)
        {
            return;
        }
        else
        {
            CancellTS.Cancel();
        }
    }

---

调用ThrowIfCancellationRequested（）后，不应吞咽异常，以便可以将任务状态的更改通知调用方（Start（）方法）。如果您接受该异常，则认为该任务已成功完成（状态=RanToCompletion），或者如果您在触发取消后立即轮询该任务，则该任务仍在运行

当您等待任务完成时，应将异常处理程序放置在调用方中

请参考MSDN中的示例