C#/.NET应用程序编程开发中多线程ThreadStart如何传递参数？

问题描述

C#/.NET应用程序编程开发中，我们可以new Thread()来开启多线程，其中Thread类可以接收ThreadStart类型的参数，如下：

public static void Main()
{
    var th = new Thread(new ThreadStart(() =>
    {
        Thread.Sleep(5000);
        Console.WriteLine("sub thread task running...");
    }))
    {
        IsBackground = true
    };
    th.Start();
    Console.WriteLine("main thread...");
    Console.ReadLine();
}

这里的ThreadStart类型无法传递参数，如果我们要向ThreadStart传递参数，应该如何实现呢？

方案一

使用ParameterizedThreadStart类型作为Thread()构造函数的参数，如下：

using System;
using System.Threading;

namespace ConsoleApp2
{
    class Program
    {
        public static void Main()
        {
            var name = "Rector";
            var th = new Thread(new ParameterizedThreadStart(DoWork))
            {
                IsBackground = true
            };
            th.Start(name);
            Console.WriteLine("main thread run here...");
            Console.ReadLine();
        }

        private static void DoWork(object name)
        {
            Thread.Sleep(2000);
            Console.WriteLine("sub thread task running,parameter is {0}...", name);
        }
    }
}

方案二

使用ParameterizedThreadStart传递参数时，只能传递一个object的参数，如果要传递多个并且是强类型的参数时ParameterizedThreadStart的方式无能为力了。

查看Thread类的构造函数可知，Thread有3个被重载的构造函数，我们可以使用ThreadStart类型的lambda方式实现多参数传递，如下：

using System;
using System.Threading;

namespace ConsoleApp2
{
    class Program
    {
        public static void Main()
        {
            var firstName = "Rector";
            var lastName = "Liu";
            var th = new Thread(() => DoWork(firstName, lastName))
            {
                IsBackground = true
            };
            th.Start();
            Console.WriteLine("main thread...");
            Console.ReadLine();
        }

        private static void DoWork(string firstName, string lastName)
        {
            Thread.Sleep(2000);
            Console.WriteLine("sub thread task running,firstName is:{0}, lastName is:{1}...", firstName, lastName);
        }
    }
}