C# -- 使用委托 delegate 执行异步操作

C# -- 使用委托 delegate 执行异步操作

委托是一种安全地封装方法的类型，它与 C 和 C++ 中的函数指针类似。 与 C 中的函数指针不同，委托是面向对象的、类型安全的和保险的。

委托的类型由委托的名称定义。

1. 使用委托异步执行方法

    class Program
    {
        public delegate void myWorking(string s);

        static void Main(string[] args)
        {
            Console.WriteLine("主线程开始....线程ID:{0}", Thread.CurrentThread.ManagedThreadId);
            myWorking myWork1 = new myWorking(w1 => Working(w1));
            myWorking myWork2 = new myWorking(w2 => Working(w2));
            myWorking myWork3 = new myWorking(w3 => Working(w3));
            myWorking myWork4 = new myWorking(w4 => Working(w4));
            myWorking myWork5 = new myWorking(w5 => Working(w5));
            
            //回调函数
            AsyncCallback callback=new AsyncCallback(s=>Console.WriteLine("执行完成，线程ID:{0}",Thread.CurrentThread.ManagedThreadId));

            //BeginInvoke异步执行，会新启动其他线程去执行代码
            myWork1.BeginInvoke("唱歌", callback,null);
            myWork2.BeginInvoke("写代码", callback, null);
            myWork3.BeginInvoke("查资料", callback, null);
            myWork4.BeginInvoke("交作业", callback, null);
            myWork5.BeginInvoke("检查", callback, null);

            Console.WriteLine("主线程结束....线程ID:{0}", Thread.CurrentThread.ManagedThreadId);
            Console.ReadKey();
        }

        private static void Working(string strWork)
        {
            Console.WriteLine(strWork+".....线程ID:{0}",Thread.CurrentThread.ManagedThreadId);
            Thread.Sleep(3000);
        }
    }

2. 执行结果：