C# 异步激发的事件能否在窗体上同步运行?
[VS 2010 Beta版与.Net Framework 3.5版] 我编写了一个C#组件,用于异步监视套接字并在接收数据时引发事件。我将VB窗体设置为在引发事件时显示消息框。我注意到,当组件同步引发事件时,消息框会阻止组件代码并锁定表单,直到用户关闭消息。当异步引发时,它既不会阻塞代码,也不会锁定表单 我想要的是一种引发事件的方法,它不会阻止代码,而是在与表单相同的线程上调用(这样它会锁定表单,直到用户选择一个选项) 你能帮我吗? 谢谢 [组件]C# 异步激发的事件能否在窗体上同步运行?,c#,.net,vb.net,asynchronous,delegates,C#,.net,Vb.net,Asynchronous,Delegates,[VS 2010 Beta版与.Net Framework 3.5版] 我编写了一个C#组件,用于异步监视套接字并在接收数据时引发事件。我将VB窗体设置为在引发事件时显示消息框。我注意到,当组件同步引发事件时,消息框会阻止组件代码并锁定表单,直到用户关闭消息。当异步引发时,它既不会阻塞代码,也不会锁定表单 我想要的是一种引发事件的方法,它不会阻止代码,而是在与表单相同的线程上调用(这样它会锁定表单,直到用户选择一个选项) 你能帮我吗? 谢谢 [组件] using System; using Sy
using System;
using System.Threading;
using System.ComponentModel;
namespace mySpace
{
public delegate void SyncEventHandler(object sender, SyncEventArgs e);
public delegate void AsyncEventHandler(object sender, AsyncEventArgs e);
public class myClass
{
readonly object syncEventLock = new object();
readonly object asyncEventLock = new object();
SyncEventHandler syncEvent;
AsyncEventHandler asyncEvent;
private delegate void WorkerDelegate(string strParam, int intParam);
public void DoWork(string strParam, int intParam)
{
OnSyncEvent(new SyncEventArgs());
AsyncOperation asyncOp = AsyncOperationManager.CreateOperation(null);
WorkerDelegate delWorker = new WorkerDelegate(ClientWorker);
IAsyncResult result = delWorker.BeginInvoke(strParam, intParam, null, null);
}
private void ClientWorker(string strParam, int intParam)
{
Thread.Sleep(2000);
OnAsyncEvent(new AsyncEventArgs());
OnAsyncEvent(new AsyncEventArgs());
}
public event SyncEventHandler SyncEvent
{
add { lock (syncEventLock) syncEvent += value; }
remove { lock (syncEventLock) syncEvent -= value; }
}
public event AsyncEventHandler AsyncEvent
{
add { lock (asyncEventLock) asyncEvent += value; }
remove { lock (asyncEventLock) asyncEvent -= value; }
}
protected void OnSyncEvent(SyncEventArgs e)
{
SyncEventHandler handler;
lock (syncEventLock) handler = syncEvent;
if (handler != null) handler(this, e, null, null); // Blocks and locks
//if (handler != null) handler.BeginInvoke(this, e, null, null); // Neither blocks nor locks
}
protected void OnAsyncEvent(AsyncEventArgs e)
{
AsyncEventHandler handler;
lock (asyncEventLock) handler = asyncEvent;
//if (handler != null) handler(this, e, null, null); // Blocks and locks
if (handler != null) handler.BeginInvoke(this, e, null, null); // Neither blocks nor locks
}
}
}
Imports mySpace
Public Class Form1
Public WithEvents component As New mySpace.myClass()
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
component.DoWork("String", 1)
End Sub
Private Sub component_SyncEvent(ByVal sender As Object, ByVal e As pbxapi.SyncEventArgs) Handles component.SyncEvent
MessageBox.Show("Synchronous event", "Raised:", MessageBoxButtons.OK)
End Sub
Private Sub component_AsyncEvent(ByVal sender As Object, ByVal e As pbxapi.AsyncEventArgs) Handles component.AsyncEvent
MessageBox.Show("Asynchronous event", "Raised:", MessageBoxButtons.OK)
End Sub
End Class
[表格]
using System;
using System.Threading;
using System.ComponentModel;
namespace mySpace
{
public delegate void SyncEventHandler(object sender, SyncEventArgs e);
public delegate void AsyncEventHandler(object sender, AsyncEventArgs e);
public class myClass
{
readonly object syncEventLock = new object();
readonly object asyncEventLock = new object();
SyncEventHandler syncEvent;
AsyncEventHandler asyncEvent;
private delegate void WorkerDelegate(string strParam, int intParam);
public void DoWork(string strParam, int intParam)
{
OnSyncEvent(new SyncEventArgs());
AsyncOperation asyncOp = AsyncOperationManager.CreateOperation(null);
WorkerDelegate delWorker = new WorkerDelegate(ClientWorker);
IAsyncResult result = delWorker.BeginInvoke(strParam, intParam, null, null);
}
private void ClientWorker(string strParam, int intParam)
{
Thread.Sleep(2000);
OnAsyncEvent(new AsyncEventArgs());
OnAsyncEvent(new AsyncEventArgs());
}
public event SyncEventHandler SyncEvent
{
add { lock (syncEventLock) syncEvent += value; }
remove { lock (syncEventLock) syncEvent -= value; }
}
public event AsyncEventHandler AsyncEvent
{
add { lock (asyncEventLock) asyncEvent += value; }
remove { lock (asyncEventLock) asyncEvent -= value; }
}
protected void OnSyncEvent(SyncEventArgs e)
{
SyncEventHandler handler;
lock (syncEventLock) handler = syncEvent;
if (handler != null) handler(this, e, null, null); // Blocks and locks
//if (handler != null) handler.BeginInvoke(this, e, null, null); // Neither blocks nor locks
}
protected void OnAsyncEvent(AsyncEventArgs e)
{
AsyncEventHandler handler;
lock (asyncEventLock) handler = asyncEvent;
//if (handler != null) handler(this, e, null, null); // Blocks and locks
if (handler != null) handler.BeginInvoke(this, e, null, null); // Neither blocks nor locks
}
}
}
Imports mySpace
Public Class Form1
Public WithEvents component As New mySpace.myClass()
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
component.DoWork("String", 1)
End Sub
Private Sub component_SyncEvent(ByVal sender As Object, ByVal e As pbxapi.SyncEventArgs) Handles component.SyncEvent
MessageBox.Show("Synchronous event", "Raised:", MessageBoxButtons.OK)
End Sub
Private Sub component_AsyncEvent(ByVal sender As Object, ByVal e As pbxapi.AsyncEventArgs) Handles component.AsyncEvent
MessageBox.Show("Asynchronous event", "Raised:", MessageBoxButtons.OK)
End Sub
End Class
是的,您可以使用窗体(或任何控件)上的方法在UI线程中以同步方式同步和执行任何委托。您需要调用窗体的BeginInvoke
方法(仅限),该方法将在窗体的UI线程上运行委托(从而阻止窗体),不阻塞调用线程以等待调用完成
如果您没有对表单实例的引用,可以从UI线程保存
SynchronizationContext.Current
,然后在SynchronizationContext
实例上调用Post
,这将是等效的。如果我理解正确,我认为您以错误的方式处理问题
我认为无论何时显示消息框,都需要显式禁用表单上的控件,然后在用户关闭消息框时重新启用它们
请澄清;是否希望UI线程在显示框时发送消息?(例如,表单会自动重新绘制)我建议使用
SynchronizationContext.Post
,在委托中传递对话框代码。这不会阻止(其他线程的)代码,但会在UI线程中执行对话框代码,因此它将被阻止。我不认为这是他的意思。他想要一种简单的方法来“锁定”表单,但他仍然希望自己的UI线程能够传递消息。无论如何,这就是我读他的问题的方式。Invoke
将阻止组件代码,我认为OP需要使用BeginInvoke
在UI线程上执行,但不会阻止组件代码。我尝试使用Invoke()而不是BeginInvoke(),它在表单上工作,但会阻止组件代码。此外,在使用BeginInvoke()调用的方法中调用Invoke()不会改变任何内容。(我在哪里可以找到帖子和评论的格式指南?@cyclotis04-你可以在这里找到一些格式语法,你错了。他需要在UI线程上调用ShowDialog
。他想让它发送消息,但不响应用户输入。如果我在不使用任何BeginInvoke()的情况下引发事件,则消息框会锁定表单,直到用户做出选择。如果涉及到任何BeginInvoke(),则表单不会锁定。@cyclotis04-我确信SLaks是正确的。关键是你在VB窗体上调用BeginInvoke。如果你调用委派.BeginInvoke
,你也必须调用EndInvoke
。既然我理解了他的要求,我相信你是正确的+1好的,我想我理解为什么需要这样做,但我有点困惑如何让它工作。在哪里保存UI线程的上下文,以及如何将其传递给异步线程?将其从UI线程保存到类中的字段中(可能在DoWork
)