C# 带取消的WriteLineAsync

我将我的方法扩展到了

async

，但是我希望能够通过用户请求和超时时间来取消，但是

WriteLineAsync

不支持取消令牌的移交。我尝试了嵌套任务，但不起作用。有人能支持我吗

public async Task tapAsync(int x, int y, int timeouttime)
{
    CancellationTokenSource cts;
    cts = new CancellationTokenSource();
    await Task.Run(async() =>
    {
       try
       {
           cts.CancelAfter(timeouttime);
           await myWriter.WriteLineAsync("input tap " + x.ToString() + " " + y.ToString());
           await myWriter.FlushAsync();
           await Task.Delay(2000);
       }
       catch (OperationCanceledException)
       {
           Console.WriteLine("canceled");
       }
    }, cts.Token);
    cts = null;
}

---

至少到目前为止，您还不能取消

WriteLineAsync

本身

您最多只能在两次操作之间取消：

public async Task TapAsync(int x, int y, int timeouttime)
{
    CancellationTokenSource cts;
    cts = new CancellationTokenSource();
    cts.CancelAfter(timeouttime);
    return TapAsync(x, y, source.Token);
    await myWriter.WriteLineAsync("input tap " + x.ToString() + " " + y.ToString());
    token.ThrowIfCancellationRequested();
    await myWriter.FlushAsync();
    token.ThrowIfCancellationRequested();
    await Task.Delay(2000, token);
}

为了清晰和灵活，我可能会将其拆分为：

public Task TapAsync(int x, int y, int timeouttime)
{
    CancellationTokenSource cts;
    cts = new CancellationTokenSource();
    cts.CancelAfter(timeouttime);
    return TapAsync(x, y, source.Token);
}

public async Task TapAsync(int x, int y, CancellationToken token)
{
    token.ThrowIfCancellationRequested();
    await myWriter.WriteLineAsync("input tap " + x.ToString() + " " + y.ToString());
    token.ThrowIfCancellationRequested();
    await myWriter.FlushAsync();
    token.ThrowIfCancellationRequested();
    await Task.Delay(2000, token);
}

---

myWriter的类型是什么？您的文本流将是垃圾。因此，我们不妨结束它并关闭（）它，这样会猛拉地板垫，导致异步写入失败。