问题描述
在 C#.NET 中,我编写了以下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
}
}
它只等待 3 秒(完成它的工作),然后引发指定事件或调用委托.直到这里没有问题,一切正常.但是当我观看 'Thread.CurrentThread.ManagedThreadId' 时,我发现它是后台线程!也许这很正常,但我怎样才能防止这种行为?如果您测试 'System.Windows.Forms.Timer' 组件并处理其 'Tick' 事件,您可以看到 'Thread.CurrentThread.ManagedThreadId' 没有从主线程 ID 更改为其他任何内容.
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.
我能做什么?
推荐答案
如果你使用的是 Windows 窗体,你可以这样做:
If You are using Windows Forms you can do something like this:
在您的表单中添加属性
In your Form add property
private readonly System.Threading.SynchronizationContext context;
public System.Threading.SynchronizationContext Context
{
get{ return this.context;}
}
在您的表单构造函数中设置属性
In Your Form constructor set the property
this.context= WindowsFormsSynchronizationContext.Current;
使用此属性将其作为构造函数参数传递给您的后台工作人员.这样,您的工作人员将了解您的 GUI 上下文.在您的后台工作人员中创建类似的属性.
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;
}
改变你的 Done()
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 中您应该始终在您的 GUI 线程中.
In DoneSynchronized You should always be in Your GUI thread.
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