wpf custom control events

Question

I want to create a custom wpf control that contains a Button and a ContentPresenter. As WPF controls are supposed to be lookless I created a class that is supposed to contain my control's behaviour and I put default style for the control inside generic.xaml file. So far so good.

But how do I make my button raise an event (routed event?) and handle it in my control's class? I figured out that I can add code behind file for the ResourceDictionary from generic.xaml and put my event handlers there, but that would associate behaviour of my control with its template and is therefore not desirable. Another idea I have seen (but not yet tried) is to use TemplatePart mechanism to locate some key controls inside the template and subscribe to events in code. But that does not seem flexible enough for me because it may happen that the user of my control will want to replace button with a control that does not have any event I know of at the time of designing my control.

So how do I raise event in XAML when button is clicked and subscribe to it in my control's code file?

Emond · Accepted Answer · 2012-05-22 05:51:46Z

2

Override the OnApplyTemplate method of the control.

That is where you know the template has been applied and you can use GetTemplateChild to get a reference to a control.

E.g.:

public override void OnApplyTemplate()
{
    base.OnApplyTemplate();
    var myButton = this.GetTemplateChild("myButton") as Button;
    if(myButton != null)
    {
        myButton.Click += ...;
}

answered May 22, 2012 at 5:51

Emond

50.8k11 gold badges86 silver badges118 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Tomasz Grobelny Over a year ago

This method assumes that I know that the control template has a "Button" named "myButton" and that I want to subscribe to "Click" event. I do not want to make such assumptions. The user should be able to change it to "Label" named "myLabel" that raises "MouseEnter" event.

Emond Over a year ago

in that case make sure that the template triggers a Command and handle the implement the Execute method. Using blend behaviors you can have any event execute the command.

Tomasz Grobelny Over a year ago

I tried reading about commands, but I still don't know how to use them in this case. Do I need to create my own object implementing ICommand interface or can I reuse generic commands? How do I reference it in XAML? I have seen some examples that claim the command has to be a public static property in static class - then how do I pass instance of the object on which the operation should be performed to the command? Do I need to use CommandTarget?

Tomasz Grobelny Over a year ago

I finally managed to find an article that describes how to solve my problem: keyvan.io/how-to-add-commands-to-custom-wpf-control While your answer is not exactly what I expected, it helped me to some degree so adding +1.

Collectives™ on Stack Overflow

wpf custom control events

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related