参见英文答案 > Captured variable in a loop in C#                                    8个
我想要做的很简单,
我扫描一个字符串列表,然后,我将每个字符串传递给一个新的线程进行打印.

using System;
using System.Collections.Generic;
using System.Threading;

namespace MultithreadingSynchronization
{
    class Program
    {
        static void Main(string[] args)
        {
            List<string> stringList = new List<string> { "server1", "server2", "server3", "server4", "server5", "server6", "server7", "server8", "server9"};

            foreach (string server in stringList)
            {
                ThreadStart work = delegate { Threadjob(server); };
                new Thread(work).Start();
                //Thread.Sleep(10); // 10 ms delay of main thread
            }
        }

        public static void Threadjob(object server)
        {
            Console.WriteLine(server);
        }
    }
}

由于某种原因,有些线程接收到错误的值,因此,输出会显示一些重复的字符串,并且还会遗漏一些字符串.
我期待这个输出(顺序并不重要)：

server1
server2
server3
server4
server5
server6
server7
server8
server9

但是,有时我得到这个：

server3
server2
server5
server5
server7
server4
server8
server9
server9

有时我得到这个：

server2
server2
server4
server3
server6
server7
server7
server8
server9

等等

事实上,如果我在每个线程创建后延迟,我会得到我期望得到的.

任何的想法？

解决方法:

您应该制作变量的本地副本.
试试这个：

    foreach (string server in stringList)
    {
        string local = server;
        ThreadStart work = delegate { Threadjob(local); };
        new Thread(work).Start();
        //Thread.Sleep(10); // 10 ms delay of main thread
    }

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