WPF UserControl事件

问题描述

大家好！

我已经进行了用户控制(可以说它很像按钮).当用户至少按下我的控件2秒钟时，我的控件将提供典型的Click事件以及自定义的Press事件(在这种情况下，不会发送click事件).按下事件是通过使用计时器经过的事件来确定的.

问题是，使用控件时，我可以在单击事件中访问我的发件人，但在新闻事件中却收到错误消息调用线程无法访问该对象，因为另一个线程拥有它."我很困惑..

这是我的customcontrol的代码片段

hi all!

I have made user control (could say it is pretty much like button). My control offers typical click event and also custom press event when user has pressed my control atleast 2 seconds (in this case click event is not sent). Press event is determinated by using timer elapsed event.

The problem is that when using my control i can access my sender in click event but in press event i got error "The calling thread cannot access this object because a different thread owns it." Im confused..

Here is codesnippet from my customcontrol

//timerstarts when user presses button, after 2 seconds this will be launced.     
private void aTimer_Elapsed(object source, ElapsedEventArgs e)
{
aTimer.Stop();
OnPressEvent();
}

//my Press event               
public event EventHandler<eventargs> PressEvent;

private void OnPressEvent()
{
     IsPressEventLaunced = true; //this flag prevents click event to be send

     // Copy to a temporary variable to be thread-safe.
     EventHandler<eventargs> temp = PressEvent;

   if (temp != null)
   {
    temp(this, new EventArgs()); //The problem!! I can send 'this' BUT in client side cannnot use 'sender'
   }
}

//my click event
public event RoutedEventHandler Click;


//happens when mouse is released, sends click event unless pressevent is launched
private void myControl_PreviewMouseUp(object sender, MouseButtonEventArgs e)
{
aTimer.Stop();


if (!IsPressEventLaunced)
    {
     if (null != Click)
        Click(sender, e);
    }
}</eventargs></eventargs>

这是客户端的摘录

And here is snippet from client side

private void button_PressEvent(object sender, EventArgs e)
        {
            myControl temp = (myControl )sender as myControl ;
            //Here I cannot use sender information
        }

        private void button_Click(object sender, RoutedEventArgs e)
        {
            myControl temp = (myControl )sender as myControl;
            //Here I can access sender information
        }

希望您有想法:)

hope you got idea :)

推荐答案

private void OnPressEvent()
{
     if(!Dispatcher.CheckAccess())
     {
          Dispatcher.Invoke((Action) OnPressEvent, null);
          return;
     }

     IsPressEventLaunced = true; //this flag prevents click event to be send

     // Copy to a temporary variable to be thread-safe.
     EventHandler<eventargs> temp = PressEvent;

   if (temp != null)
   {
    temp(this, new EventArgs()); //The problem!! I can send 'this' BUT in client side cannnot use 'sender'
   }
}

这篇关于WPF UserControl事件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！