When Raising an MouseButtonEvent from a UserControl the MainWindow have no access to MouseButtonEventArgs
Still climbing up the steep WPF Mountain, and suffering.
开发者_如何转开发I have defined a UserControl, and my MainWindow needs to retrieve the MouseButtonEventArgs coming from a control inside the UserControl (like the mouse e.GetPosition for instance)
In the UserControl code behind, I have done the Registrations and I Raise the bubbling event.
public static readonly RoutedEvent MyButtonDownEvent = EventManager.RegisterRoutedEvent("MyMouseButtonDown", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(MyUserControl));
public event RoutedEventHandler MyButtonDown {
add { AddHandler(MyButtonDownEvent, value); }
remove { RemoveHandler(MyButtonDownEvent, value); }
}
private void MyMouseButtonDownHandler(object sender, MouseButtonEventArgs e) {
RaiseEvent(new RoutedEventArgs(MyButtonDownEvent ));
}
Now in my MainWindow I declare the UserControl like this:
<local:MyUserControl MouseDown="MyUserControl_MouseDown"/>
And this code behind
private void MyUserControl_MouseDown(object sender, RoutedEventArgs e)
And I receive the events from the UserControl, but the Args are RoutedEventArgs (which is normal) but I dont have access to the MouseButtonEventArgs that I need to get the mouse e.GetPosition.
What elegant solution would you suggest in this case ?
Why do you define your own MouseDown
event while UserControl
already has a normal MouseDown event?
Anyway, if you define an event to use a RoutedEventHandler
it is hardly surprising that you'll end up being stuck with a RoutedEventHandler
. You declared it like this:
public static readonly RoutedEvent MyButtonDownEvent = EventManager.RegisterRoutedEvent("MyMouseButtonDown", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(MyUserControl));
Notice the bit where it says typeof(RoutedEventHandler)
?
If i am not mistaken your code should look like this instead:
public static readonly RoutedEvent MyButtonDownEvent =
EventManager.RegisterRoutedEvent
("MyButtonDown",
RoutingStrategy.Bubble,
typeof(MouseButtonEventHandler),
typeof(MyUserControl));
public event MouseButtonEventHandler MyButtonDown
{
add { AddHandler(MyButtonDownEvent, value); }
remove { RemoveHandler(MyButtonDownEvent, value); }
}
Example of how to propagate an existing MouseDown event to the custom event:
InitializeComponent();
this.MouseDown += (s, e) => {
RaiseEvent(new MouseButtonEventArgs(e.MouseDevice, e.Timestamp, e.ChangedButton)
{
RoutedEvent = MyButtonDownEvent
});
};
I think I finally got it (at least I hope):
If I write in the code behind:
public event EventHandler<MouseButtonEventArgs> MyRightButtonDownHandler;
public void MyRightButtonDown(object sender, MouseButtonEventArgs e) {
MyRightButtonDownHandler(sender, e);
}
Then in the consumer (MainWindow) XAML:
<local:GlobalDb x:Name="globalDb" MyRightButtonDownHandler="globalDb_MyRightButtonDownHandler"/>
And in the consumer code behind:
private void globalDb_MyRightButtonDownHandler(object sender, MouseButtonEventArgs e) {
Console.WriteLine("x= " + e.GetPosition(null).X + " y= " + e.GetPosition(null).Y);
}
Please tell me if you have a better solution (By design policy - rules established where I work - all the event handling of my application MUST appear in the XAML).
Thanks again for your help,
精彩评论