C#使用CancellationTokenSource 取消 Task的方法

private static int TaskMethod(string name, int seconds, CancellationToken token)
{
Console.WriteLine("Task {0} 运行在线程 {1} 上。是否是线程池线程: {2}",
name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
for (int i = 0; i < seconds; i ++)
{
Thread.Sleep(1000);
if (token.IsCancellationRequested) return -1;
}
return 42*seconds;
}

var cts = new CancellationTokenSource();
var longTask = new Task<int>(() => TaskMethod("Task 1", 10, cts.Token), cts.Token);
Console.WriteLine("取消前，第一个任务的状态：{0}", longTask.Status);
cts.Cancel(); //取消任务！
Console.WriteLine("取消后，第一个任务的状态：{0}",longTask.Status);
Console.WriteLine("第一个任务在被执行前就已经取消了！");

var cts = new CancellationTokenSource();
var longTask = new Task<int>(() => TaskMethod("Task 2", 10, cts.Token), cts.Token);
longTask.Start(); //启动任务
for (int i = 0; i < 5; i++)
{
Thread.Sleep(TimeSpan.FromSeconds(0.5));
Console.WriteLine(longTask.Status);
}
cts.Cancel();
for (int i = 0; i < 5; i++)
{
Thread.Sleep(TimeSpan.FromSeconds(0.5));
Console.WriteLine(longTask.Status);
}
 
Console.WriteLine("A task has been completed with result {0}.", longTask.Result);