Avalonia.EventSetter

⚠️ Not working anymore from version 11 of Avalonia as needed Avalonia interfaces and base classes are now internal. As an alternative, you can try Avalonia Behaviors See #1 and Custom Style Setter

As AvaloniaUI for now do not have an EventSetter like in WPF in styles. This package try to replicate the way EventSetter of WPF work in AvaloniaUI.

Getting started

Install the nuget

dotnet add package CodingSeb.Avalonia.EventSetter

For the designer
To make the EventSetter recognized by the designer you need to add the following line somewhere it's called by the designer. Example in App.axaml.cs

GC.KeepAlive(typeof(Avalonia.Styling.EventSetter).Assembly);

This is an hack to force the designer to load the corresponding assembly. See issue 7200 and 250 of AvaloniaUI.

Example

In MainWindow.axaml :

<StackPanel>
    <TextBox />
    <TextBox />
    <TextBox />
	
    <StackPanel.Styles>
        <Style Selector="TextBox" >
            <EventSetter Event="KeyDown" Handler="TextBox_KeyDown" />
        </Style>
    </StackPanel.Styles>
</StackPanel>

In MainWindow.axaml.cs (CodeBehind) :

private void TextBox_KeyDown(object sender, KeyEventArgs e)
{
    // What you want to do on textbox key down
}

Known issues

As Event and Handler properties on the EventSetter are string intellisense do not work. You need to know the name of the event and the handler you want to use. also the handler must have the good signature in code behind.

As the subscribe and unsubscribe of the event is done with Reflection it can be slow on a large set of StyleElements

Attached events are not supported for now.