WinUI 3 global key down/up events

Question

I would like to handle the Escape button key pressed event in a WinUI 3 application, with MVVM Toolkit. I want to use this event to close the application.

I have tried different solutions, but most of them are talking about an UIElement which must have focus. I have tried the Page KeyDown and KeyUp events, but they only trigger if there is an UIElement in the Page controls, which has focus.

In WPF I could do this by adding a MVVM command with parameter to a KeyBinding in the Windows.InputBindings.

Is there a way to obtain the same functionality in WinUI 3?

Answer 1

You can use KeybordAccelerators for this:

<Page.KeyboardAccelerators>
    <KeyboardAccelerator
        Key="Escape"
        Invoked="KeyboardAccelerator_Invoked"
        Modifiers="None" />
</Page.KeyboardAccelerators>

private void KeyboardAccelerator_Invoked(
    KeyboardAccelerator sender,
    KeyboardAcceleratorInvokedEventArgs args)
{
}

UPDATE

If you need to do your process via a command, you can use the Microsoft.Xaml.Behaviors.WinUI.Managed NuGet package.

<Page
    x:Class="KeyboardAcceleratorsExample.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:core="using:Microsoft.Xaml.Interactions.Core"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:i="using:Microsoft.Xaml.Interactivity"
    xmlns:local="using:KeyboardAcceleratorsExample"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
    mc:Ignorable="d">

    <Page.KeyboardAccelerators>
        <KeyboardAccelerator
            Key="Escape"
            Modifiers="None">
            <i:Interaction.Behaviors>
                <core:EventTriggerBehavior EventName="Invoked">
                    <core:InvokeCommandAction Command="{x:Bind ViewModel.DoSomethingCommand}" />
                </core:EventTriggerBehavior>
            </i:Interaction.Behaviors>
        </KeyboardAccelerator>
    </Page.KeyboardAccelerators>
</Page>