C＃跨线程通信 [英] C# Cross-Thread communication

问题描述

在C＃.NET，我写了下面这个简单的后台工作线程：

in C#.NET , I've written the following simple background worker thread:

public class MyBackgrounder
{
    public delegate void dlgAlert();
    public dlgAlert Alert;
    public event EventHandler eventAlert;
    Thread trd;

    public void Start()
    {
        if (trd == null || trd.ThreadState == ThreadState.Aborted)
        {
            trd = new Thread(new ThreadStart(Do));
        }
        trd.IsBackground = true;
        trd.Priority = ThreadPriority.BelowNormal;
        trd.Start();
    }

    void Do()
    {

        Thread.Sleep(3000);
        Done();
    }

    void Done()
    {
        if (Alert != null)
            Alert();
        if (eventAlert != null)
            eventAlert(this, new EventArgs());
        Kill();
    }

    public void Kill()
    {
        if (trd != null)
            trd.Abort();
        trd = null;
    }
}


static class Program
{

    [STAThread]
    static void Main()
    {
        MyBackgrounder bg = new MyBackgrounder();
        bg.eventAlert += new EventHandler(bg_eventAlert);
        bg.Alert = jobDone;
        bg.Start();
    }

    static void bg_eventAlert(object sender, EventArgs e)
    {
        // here, current thread's id has been changed
    }

    static void jobDone()
    { 
        // here, current thread's id has been changed
    }

}

这只是等待3秒（它的工作），然后引发一个特定的事件或调用一个委托。有没有问题，直到这里，一切工作正常。但是，当我观看了 Thread.CurrentThread.ManagedThreadId ，我看到它的后台线程！也许这是正常的，但我怎么能prevent这种行为？如果你测试了 System.Windows.Forms.Timer 组件并处理其勾选的事件，你可以看到 Thread.CurrentThread.ManagedThreadId 没有发生变化，从主线程ID为别的了。

It just waits for 3 seconds (does its job) and then raises an specified event or calls a delegate. there's no problem until here and everything works fine. But when i watch the 'Thread.CurrentThread.ManagedThreadId' , i see it's the background thread! maybe it's normal , but how can i prevent this behavior? if you test the 'System.Windows.Forms.Timer' component and handle its 'Tick' event , you can see that the 'Thread.CurrentThread.ManagedThreadId' has not been changed from main thread Id to anything else.

我该怎么办？

推荐答案

如果您使用的是Windows窗体，你可以做这样的事情：

If You are using Windows Forms you can do something like this:

1. 在你的窗体添加属性

1. In your Form add property

private readonly System.Threading.SynchronizationContext context;
public System.Threading.SynchronizationContext Context
{
    get{ return this.context;}
}

在窗体构造函数中设置属性

In Your Form constructor set the property

this.context= WindowsFormsSynchronizationContext.Current;

使用此属性将它传递给你的后台工作作为一个构造函数的参数。这样，你的员工会知道你的GUI环境。在你的后台工作创建类似的属性。

Use this property to pass it to Your background worker as a constructor parameter. This way your worker will know about your GUI context. Create similar property inside Your background worker.

private readonly System.Threading.SynchronizationContext context;
public System.Threading.SynchronizationContext Context
{
    get{ return this.context;}
}

public MyWorker(SynchronizationContext context)
{
    this.context = context;
}

更​​改完成（）方法：

void Done()
{
    this.Context.Post(new SendOrPostCallback(DoneSynchronized), null);
}

void DoneSynchronized(object state)
{
    //place here code You now have in Done method.
}

在DoneSynchronized你应该总是在你的GUI线程。

In DoneSynchronized You should always be in Your GUI thread.

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