CancellationTokenSource (取消令牌)

1、网络场景

public async static Task GetToday()
{
CancellationTokenSource cts = new CancellationTokenSource();
cts.CancelAfter(3000);
HttpClient client = new HttpClient();
var res = await client.GetAsync("http://www.weather.com.cn/data/sk/101110101.html", cts.Token);
var result = await res.Content.ReadAsStringAsync();
Console.WriteLine(result);

cts.Dispose();
client.Dispose();
}

2、CancellationToken 的链式反应

public async static Task Test()
{
CancellationTokenSource cts1 = new CancellationTokenSource();
CancellationTokenSource cts2 = new CancellationTokenSource();
var cts3 = CancellationTokenSource.CreateLinkedTokenSource(cts1.Token, cts2.Token);

cts1.Token.Register(() =>
{
Console.WriteLine("cts1 Canceling");
});
cts2.Token.Register(() =>
{
Console.WriteLine("cts2 Canceling");
});
cts2.CancelAfter(1000);

cts3.Token.Register(() =>
{
Console.WriteLine("root Canceling");
});

var res = await new HttpClient().GetAsync("http://www.weather.com.cn/data/sk/101110101.html", cts1.Token);
var result = await res.Content.ReadAsStringAsync();
Console.WriteLine("cts1:{0}", result);

var res2 = await new HttpClient().GetAsync("http://www.weather.com.cn/data/sk/101110101.html", cts2.Token);
var result2 = await res2.Content.ReadAsStringAsync();
Console.WriteLine("cts2:{0}", result2);

var res3 = await new HttpClient().GetAsync("http://www.weather.com.cn/data/sk/101110101.html", cts3.Token);
var result3 = await res2.Content.ReadAsStringAsync();
Console.WriteLine("cts3:{0}", result3);
}

引用原文：https://www.cnblogs.com/fanfan-90/p/12660996.html