C# 多线程

进程与线程

进程：进程就是一个应用程序，对电脑的各种资源的占用

线程：线程是程序执行的最小单位，任何操作都是线程完成的，线程依托进程存在的，一个进程可以有多个线程

无参数的子线程

 public static void ChildThread1(){Console.WriteLine("Child thread1 is starts");}

带参数的子线程

ChildThread2是带参数的子线程，所以要使用ParameterizedThreadStart类型的委托来指定子线程
如果使用的是不带参数的委托，不能使用带参数的Start方法运行线程，否则系统会抛出异常。
但使用带参数的委托，可以使用thread.Start()来运行线程，这时所传递的参数值为null。

特别注意：ParameterizedThreadStart委托的参数类型必须是object的

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;namespace ConsoleApp2
{class Test{public static void ChildThread1(){Console.WriteLine("Child thread1 is starts");}//注意：ParameterizedThreadStart委托的参数类型必须是object的public static void ChildThread2(object obj){Console.WriteLine("Child thread2 is starts,the parameter is {0}", obj);}public static void Main(){ThreadStart thread1 = new ThreadStart(ChildThread1); //通过ThreadStart委托指定子线程的方法ParameterizedThreadStart thread2 = new ParameterizedThreadStart(ChildThread2); //有参的委托Console.WriteLine("MainThread：Creating the child thread1");Console.WriteLine("MainThread：Creating the child thread2");Thread childThread1 = new Thread(thread1); //创建子线程1Thread childThread2 = new Thread(thread2);//创建子线程2childThread1.Start();    //运行子线程1childThread2.Start("子线程2的参数");//运行子线程2，传递参数，//如果使用的是不带参数的委托，不能使用带参数的Start方法运行线程，否则系统会抛出异常。//但使用带参数的委托，可以使用thread.Start()来运行线程，这时所传递的参数值为null。Console.ReadKey();}}
}

运行结果

销毁线程 Abort()

使用Abort()中止子线程.
通过抛出 threadabortexception 在运行时中止线程。这个异常不能被捕获，如果有 finally 块，控制会被送至 finally 块。

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;namespace ConsoleApp2
{class Test{public static void ChildThread1(){Console.WriteLine("Child thread1 is starts");}//注意：ParameterizedThreadStart委托的参数类型必须是object的public static void ChildThread2(object obj){Console.WriteLine("Child thread2 is starts,the parameter is {0}", obj);}public static void ChildThread3(){try{Console.WriteLine("Child thread3 starts");for (int i = 0; i < 5; i++){Thread.Sleep(100);Console.WriteLine(i);}Console.WriteLine("Child Thread3 Completed");}catch (ThreadAbortException e){Console.WriteLine("Thread Abort Exception");}finally{Console.WriteLine("Couldn't catch the thread Exception");}}public static void Main(){ThreadStart thread3 = new ThreadStart(ChildThread3);Console.WriteLine("MainThread：Creating the child thread3");Thread thread = new Thread(thread3);thread.Start();//停止主线程1000Thread.Sleep(2000);Console.WriteLine("In Main: Aborting the Child thread");thread.Abort();Console.ReadKey();}}
}

运行结果

ThreadPool和Task

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;namespace ConsoleApp2
{class Test{public static Thread t = null;public static void ChildThread1(){int i = 5;while (i > 0){Console.WriteLine(string.Format("线程【1】的i:{0} ", i));Thread.Sleep(10);i--;}Console.WriteLine("线程【1】结束");//Console.WriteLine("Child thread1 is starts");}//注意：ParameterizedThreadStart委托的参数类型必须是object的public static void ChildThread2(object obj){int i = 5;while (i > 0){Console.WriteLine(string.Format("线程【2】的i:{0} ", i));Thread.Sleep(10);i--;}Console.WriteLine("线程【2】结束");}public static void ChildThread3(){int i = 5;while (i > 0){Console.WriteLine(string.Format("线程【3】的i:{0} ", i));Thread.Sleep(10);i--;}Console.WriteLine("线程【3】结束");}public static void Main(string[] args){t = new Thread(new ThreadStart(ChildThread1));t.Start();//用线程池ThreadPool.QueueUserWorkItem(ChildThread2, new object());//用Task方法创建System.Threading.Tasks.Task.Factory.StartNew(ChildThread3);Console.ReadLine();}}
}

运行结果

线程都是独立的，