取消方法
例：
CancellationTokenSource cts = new CancellationTokenSource(); Action<CancellationToken, int> testAct = new Action<CancellationToken,int>((token,count)=> { for (int i = 0; i < count; i++) { if (token.IsCancellationRequested) { Console.WriteLine("cancel End"); break; } Console.WriteLine(DateTime.Now); Thread.Sleep(1000); } }); testAct.BeginInvoke(cts.Token , 10, null,null); Console.WriteLine("Test"); Thread.Sleep(3000); Console.WriteLine("cancel"); cts.Cancel();