Net中异步

同步和异步
1.同步是指只启动一个线程
2.异步是指同时启动多个线程
3.同步方法会卡界面，异步方法不会卡界面
原因：异步方法启动了子线程执行任务，主线程得到释放
4.同步方法会慢。异步方法会快
原因：异步启动了.多个线程执行任务，占用了更多的资源
5 异步是无序的，原因：线程的启动和执行是由操作系统决定的，是无序的。

 public partial class MainWindow : Window

    {

        public MainWindow()

        {

            InitializeComponent();

        }

        private delegate void DoSomethingHandler(string name);

        private void Async_Click(object sender, RoutedEventArgs e)

        {

            DoSomethingHandler method = t =>

                Console.WriteLine("这里是Async_Click,name={0}，当前线程ID={1}",

                t,Thread.CurrentThread.ManagedThreadId);

            method("直接调用");

            method.Invoke("Invoke");

            method.BeginInvoke("BeginInvoke", null, null);//这就是异步调用

        }

    }

 private void DoSomething(string name)

        {

            Stopwatch watch = new Stopwatch();

            watch.Start();

            Console.WriteLine("这里是Async_Click,name={0}，当前线程ID={1}",

                name, Thread.CurrentThread.ManagedThreadId);

            long lResult = 0;

            for (int i=0;i<10000000;i++)

            {

                lResult += i;

            }

            Thread.Sleep(1000);

            watch.Stop();

              Console.WriteLine("这里是Async_Click,name={0}，当前线程ID={1},计算结果是{2}，耗时{3}",

                name, Thread.CurrentThread.ManagedThreadId, lResult, watch.ElapsedMilliseconds);

        }

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Navigation;

using System.Windows.Shapes;

using System.Threading;

using System.Diagnostics;

namespace MyAsyncDemo

{

    /// <summary>

    /// MainWindow.xaml 的交互逻辑

    /// </summary>

    public partial class MainWindow : Window

    {

        public MainWindow()

        {

            InitializeComponent();

        }

        private delegate void DoSomethingHandler(string name);

        private void Async_Click(object sender, RoutedEventArgs e)

        {

            //DoSomethingHandler method = t =>

            //    Console.WriteLine("这里是Async_Click,name={0}，当前线程ID={1}", t,Thread.CurrentThread.ManagedThreadId);

            //method("直接调用");

            //method.Invoke("Invoke");

            //for (int i = 0; i < 5; i++)

            //{

            Console.WriteLine("**********************这里是Async_Click***************");

            string name = string.Format("Async_Click_{0}", 1);

           // DoSomethingHandler method = DoSomething;

            Func<string,long> method = GetSomething;

            AsyncCallback callback = t => Console.WriteLine("这里是AsyncCallback,当前线程ID={0},AsyncState={1}", Thread.CurrentThread.ManagedThreadId, t.AsyncState);

            IAsyncResult result = method.BeginInvoke(name, callback, "Eleven");//这就是异步调用

            //1. 一直等到结束,和同步的效果一样

            //result.AsyncWaitHandle.WaitOne(-1);

            //2.等待异步线程结束的第二种方式

            //while (!result.IsCompleted)

            //{

            //    Thread.Sleep(100);

            //    Console.WriteLine("异步还没有结束，请继续等待");

            //}

           /3.常用的第三种方式

            long lResult = method.EndInvoke(result);

            Console.WriteLine("结果是{0}", lResult);

            // }

            Console.WriteLine("**********************这里是Async_Click***************");

        }

        private long GetSomething(string name)

        {

            Stopwatch watch = new Stopwatch();

            watch.Start();

            Console.WriteLine("这里是GetSomething,name={0}，当前线程ID={1}",

                name, Thread.CurrentThread.ManagedThreadId);

            long lResult = 0;

            for (int i = 0; i < 10000000; i++)

            {

                lResult += i;

            }

            Thread.Sleep(1000);

            watch.Stop();

            Console.WriteLine("这里是GetSomething,name={0}，当前线程ID={1},计算结果是{2}，耗时{3}",

              name, Thread.CurrentThread.ManagedThreadId, lResult, watch.ElapsedMilliseconds);

            return lResult;

        }

        private void DoSomething(string name)

        {

            Stopwatch watch = new Stopwatch();

            watch.Start();

            Console.WriteLine("这里是Async_Click,name={0}，当前线程ID={1}",

                name, Thread.CurrentThread.ManagedThreadId);

            long lResult = 0;

            for (int i=0;i<10000000;i++)

            {

                lResult += i;

            }

            Thread.Sleep(1000);

            watch.Stop();

              Console.WriteLine("这里是Async_Click,name={0}，当前线程ID={1},计算结果是{2}，耗时{3}",

                name, Thread.CurrentThread.ManagedThreadId, lResult, watch.ElapsedMilliseconds);

        }

        private void Sync_Click(object sender, RoutedEventArgs e)

        {

            for (int i = 0; i < 5;i++ )

            {

                string name = string.Format("Sync_Click_{0}", i);

                DoSomething(name);

            }

        }

    }

}

巴特西

Net中异步

最新文章

热门文章