avaloniaui

How to get OnKeyDown event from View into ViewModel

I am trying to convert an old WPF MvvmCross project into Avalonia UI MVVM but I don't find information about how to pass the key into the ViewModel.

In MvvmCross I had a function

private async void OnKeyboardMessage(KeyboardMessage keyMessage)
{
    System.Diagnostics.Debug.WriteLine("Keyboard Message from MainWindow:" + keyMessage.Key.ToString());
    if (keyMessage.Key == "F5") {
        UpdateInformation();
    }
}

in my ViewModel with which I could get the F5 key.

In Avalonia UI I could get the key input with:

protected override void OnKeyDown(KeyEventArgs e)
    {
        System.Diagnostics.Debug.WriteLine(e.Key);
        base.OnKeyDown(e);
    }

In the View, but I do not understand how it can be transferred to the ViewModel.

Can someone please assist?

Solution

  • You would typically use a KeyBinding with an appropriate view model command:

    <Window.KeyBindings>
    <KeyBinding Gesture="F5" Command="{Binding UpdateInformationCommand}"/>
</Window.KeyBindings>

    Assuming you are using CommunityToolkit.Mvvm, the command could be declared like this:

    using CommunityToolkit.Mvvm.Input;
...

[RelayCommand]
private void UpdateInformation()
{
    ...
}