c# Parallel 並行運算 異步處理

var list = new List<string> {
                "https://www.baidu.com","https://associates.amazon.cn/","https://www.amazon.cn","https://www.aliyun.com","http://www.answers.com/"
            };
            Stopwatch sw1 = new Stopwatch();
            sw1.Start();
            Parallel.For(0, list.Count, i => {
                WebClient myWebClient = new WebClient();
                Stopwatch sw = new Stopwatch();
                sw.Start();
                myWebClient.OpenRead(list[i]);
                sw.Stop();
                Console.WriteLine("獲取" + list[i] + " 耗時" + sw.ElapsedMilliseconds);
            });
            sw1.Stop();
            Console.WriteLine("執行完成 共耗時"+sw1.ElapsedMilliseconds);
            //Console.ReadKey();

            //也能夠用foreach
            Parallel.ForEach(list, i =>
            {
                Console.WriteLine(i);
            });

運行結果：

獲取https://www.baidu.com 耗時171
獲取https://www.aliyun.com 耗時214
獲取https://www.amazon.cn 耗時334
獲取https://associates.amazon.cn/ 耗時378
獲取http://www.answers.com/ 耗時1249
執行完成 共耗時1259
https://www.baidu.com
http://www.answers.com/
https://associates.amazon.cn/
https://www.aliyun.com
https://www.amazon.cn
請按任意鍵繼續. . .