C#非同步和委託

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以上兩種顯示方法都實現傳回值寫法，無傳回值兩種方法基本無區別。

由執行時間結果看出，非同步可以直接結束主線程，方法也不需要主線程處理過多的代碼。

委託需要在主線程編寫代碼，並且寫法有些複雜。

using System;using System.Threading;using System.Threading.Tasks;using System.Windows.Forms;namespace AsyncAwait{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void Form1_Load(object sender, EventArgs e)        {            Control.CheckForIllegalCrossThreadCalls = false;        }        private void btclear_Click(object sender, EventArgs e)        {            tbshow.Text = "";        }        private void showMsg(string sMsg)        {            tbshow.Text += Thread.CurrentThread.ManagedThreadId + sMsg + DateTime.Now.ToString() + "\r\n";        }        private void btRun_Click(object sender, EventArgs e)        {            //非同步，分線程處理，多次點擊，還可以等待返回結果。            asyncTask();            showMsg("btRun_asyncTaskClick.end..");        }        public async void asyncTask()        {            string x = await asyncTask2();            showMsg(x);            Thread.Sleep(1000);            showMsg("asyncTask.end");        }        public async Task<string> asyncTask2()        {            return await Task.Run(() =>            {                //類比一個超大工作量的進程                showMsg("run..BeginInvoke.start.");                Random rd = new Random();                Thread.Sleep(rd.Next(3000, 6000));                showMsg("run..BeginInvoke.end.");                return "傳回值：asyncTask2End" + DateTime.Now.ToString();            });        }        public delegate void MainFun(string a,out string b);        private void btInvoke_Click(object sender, EventArgs e)        {            string sReturn = "";            //委託當執行EndInvoke時，線程被鎖死了，無法多次點擊            MainFun myMainFun = new MainFun(BeginInvoke);            IAsyncResult myIAsyncResult = myMainFun.BeginInvoke("a", out sReturn, null, null);            myMainFun.EndInvoke(out sReturn,myIAsyncResult);            showMsg(sReturn);            Thread.Sleep(1000);            showMsg("runInvoke.end..");        }        public void BeginInvoke(string a,out string b)        {            //類比一個超大工作量的進程            showMsg("run..BeginInvoke.start.");            Random rd = new Random();            Thread.Sleep(rd.Next(3000, 6000));            showMsg("run..BeginInvoke.end.");            b = "傳回值：BeginInvokeEnd" + DateTime.Now.ToString();        }        private void btrun2_Click(object sender, EventArgs e)        {            string sReturn = "";            BeginInvoke("a",out sReturn);            showMsg("run.end..");        }    }}

 

C#非同步和委託