C#开启线程的四种方式示例详解

 public static void Main(string[] args){
  Action<int,int> a=add;
  a.BeginInvoke(3,4,null,null);//前两个是add方法的参数，后两个可以为空
  Console.WriteLine("main()");
  Console.ReadKey();
 }
 static void add(int a,int b){
  Console.WriteLine(a+b);
 }

    using System;
        using System.Threading;
         public static void Main(string[] args){
  Thread t=new Thread(DownLoadFile_My);//创建了线程还未开启
  t.Start("http://abc/def/**.mp4");//用来给函数传递参数，开启线程
  Console.WriteLine("main()");
  Console.ReadKey();
 }
 //thread开启线程要求：该方法参数只能有一个，且是object类型
 static void DownLoadFile_My(object filePath){
  Console.WriteLine("开始下载："+filePath);
  Thread.Sleep(2000);
  Console.WriteLine("下载完成！");
 }

 public static void Main(string[] args){
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  ThreadPool.QueueUserWorkItem(DownLoadFile_My);
  Console.WriteLine("main()");
  Console.ReadKey();
 }
 static void DownLoadFile_My(object state){
  Console.WriteLine("开始下载...  线程ID："+Thread.CurrentThread.ManagedThreadId);
  Thread.Sleep(2000);
  Console.WriteLine("下载完成！");
 }

using System;
using System.Threading;
using System.Threading.Tasks;
 public static void Main(string[] args){
  Task t=new Task(DownLoadFile_My);
  t.Start();
  Console.WriteLine("main()");
  Console.ReadKey();
 }
 static void DownLoadFile_My( ){
  Console.WriteLine("开始下载...  线程ID："+Thread.CurrentThread.ManagedThreadId);
  Thread.Sleep(2000);
  Console.WriteLine("下载完成！");
 }

 public static void Main(string[] args){
  TaskFactory tf=new TaskFactory();
  tf.StartNew(DownLoadFile_My);
  Console.WriteLine("main()");
  Console.ReadKey();
 }
 static void DownLoadFile_My( ){
  Console.WriteLine("开始下载...  线程ID："+Thread.CurrentThread.ManagedThreadId);
  Thread.Sleep(2000);
  Console.WriteLine("下载完成！");
 }