c# - Foreach thread.join，没有按预期工作，如何解决？

Question

我想在几个线程中运行一些方法，这个方法需要一些参数。当我尝试执行它时，我的测试没有通过，因为一些线程无法结束。但是，在函数结束时我使用 Foreach { thread.join } 这是我的代码:(路径 - 一些对象的列表。解析 - 带有来自路径的对象的方法。)

public void RunAsync()
{
    Thread[] threadArr = new Thread[Paths.Count];
    var pathsArr = Paths.ToArray();

    for (int i = 0; i < PathsArr.Length; i++)
    {
        threadArr[i] = new Thread(new ParameterizedThreadStart(Parse));
        threadArr[i].Start((PathsArr[i]));
    }

    foreach (var thread in threadArr)
    {
        thread.Join();
    }
}

在这种情况下，我该如何修复它或需要使用哪些构造/技术？我想在几个线程中执行此操作，因为同步执行此操作时间太长。

Answer 1

Thread.Join() 将阻止您当前的线程。这意味着每个 foreach 循环都将在最后一次运行后执行。

我想你想要Start()你的线程来并行执行它们。

这里有一个例子:

// Example-Work-Method
public static void MyAction(int waitSecs)
{
    Console.WriteLine("Starting MyAction " + waitSecs);
    Thread.Sleep(waitSecs * 1000);
    Console.WriteLine("End MyAction " + waitSecs);
}

public static void Main(string[] args)
{
    // We create a bunch of actions which we want to executte parallel
    Action[] actions = new Action[]
        {
            new Action(() => MyAction(1)),
            new Action(() => MyAction(2)),
            new Action(() => MyAction(3)),
            new Action(() => MyAction(4)),
            new Action(() => MyAction(5)),
            new Action(() => MyAction(6)),
            new Action(() => MyAction(7)),
            new Action(() => MyAction(8)),
            new Action(() => MyAction(9)),
            new Action(() => MyAction(10)),
        };

    // create a thread for each action
    Thread[] threads = actions.Select(s => new Thread(() => s.Invoke())).ToArray();

    // Start all threads
    foreach (Thread t in threads)
    {
        t.Start();
    }
    // This will "instantly" outputted after start. It won't if we'd use Join()
    Console.WriteLine("All threads are running..");

    // And now let's wait for the work to be done.
    while (threads.Any(t => t.ThreadState != ThreadState.Stopped))
        Thread.Sleep(100);

    Console.WriteLine("Done..");
}

您可能应该问问自己是否要调用此方法 Async。 c# 中的异步方法带来了一些其他机制。看看这个:https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/async