C#線程控制淺析
在C#中,C#線程控制是如何開(kāi)始的呢?線程入口是通過(guò)ThreadStart代理(delegate)來(lái)提供的,你可以把ThreadStart理解為一個(gè)函數(shù)指針,指向線程要執(zhí)行的函數(shù),當(dāng)調(diào)用Thread.Start()方法后,線程就開(kāi)始執(zhí)行ThreadStart所代表或者說(shuō)指向的函數(shù)。
打開(kāi)你的VS.net,新建一個(gè)控制臺(tái)應(yīng)用程序(Console Application),編寫(xiě)完全C#線程控制的代碼示例:
- using System;
- using System.Threading;
- namespace ThreadTest{
- public class Alpha{
- public void Beta(){
- while (true){
- Console.WriteLine(
- "Alpha.Beta is running in its own thread.");
- }
- }
- };
- public class Simple{
- public static int Main(){
- Console.WriteLine("Thread Start/Stop/Join Sample");
- Alpha oAlpha = new Alpha();
- file://這里創(chuàng)建一個(gè)線程,使之執(zhí)行Alpha類(lèi)的Beta()方法
- Thread oThread = new Thread(new ThreadStart(oAlpha.Beta));
- oThread.Start();
- while (!oThread.IsAlive)
- Thread.Sleep(1);
- oThread.Abort();
- oThread.Join();
- Console.WriteLine();
- Console.WriteLine("Alpha.Beta has finished");
- try {
- Console.WriteLine("Try to restart the Alpha.Beta thread");
- oThread.Start();
- }
- catch (ThreadStateException){
- Console.Write(
- "ThreadStateException trying to restart Alpha.Beta. ");
- Console.WriteLine(
- "Expected since aborted threads cannot be restarted.");
- Console.ReadLine();
- }
- return 0;
- }
- }
- }
這段C#線程控制程序包含兩個(gè)類(lèi)Alpha和Simple,在創(chuàng)建線程oThread時(shí)我們用指向Alpha.Beta()方法的初始化了ThreadStart代理(delegate)對(duì)象,當(dāng)我們創(chuàng)建的線程oThread調(diào)用oThread.Start()方法啟動(dòng)時(shí),實(shí)際上程序運(yùn)行的是Alpha.Beta()方法:
- Alpha oAlpha = new Alpha();
- Thread oThread = new Thread(new ThreadStart(oAlpha.Beta));
- oThread.Start();
然后在Main()函數(shù)的while循環(huán)中,我們進(jìn)行C#線程控制使用靜態(tài)方法Thread.Sleep()讓主線程停了1ms,這段時(shí)間CPU轉(zhuǎn)向執(zhí)行線程oThread。然后我們?cè)噲D用Thread.Abort()方法終止線程oThread,注意后面的oThread.Join(),Thread.Join()方法使主線程等待,直到oThread線程結(jié)束。你可以給Thread.Join()方法指定一個(gè)int型的參數(shù)作為等待的最長(zhǎng)時(shí)間。之后,我們?cè)噲D用Thread.Start()方法重新啟動(dòng)線程oThread,但是顯然Abort()方法帶來(lái)的后果是不可恢復(fù)的終止線程,所以***程序會(huì)拋出ThreadStateException異常。
關(guān)于C#線程控制的基本內(nèi)容就向你介紹到這里,希望對(duì)你了解和學(xué)習(xí)C#線程控制有所幫助。
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