CODEWITHSUNDEEP
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Marcus L
Marcus L

Reputation: 4080

Can I use KeyBinding on KeyUp?

Is there a way to use KeyBinding and execute the command on OnKeyUp in XAML?

If I want to bind the left-ALT key to execute my own command for menu access, because KeyBinding executes commands on OnKeyDown, I get some unwanted behaviour. For example, when tabbing out of the application with Alt+Tab the command will fire, and if the key is held down, the command is retriggered until the key is released.

I know the ALT is a modifier key, and a bit of a special case, but by waiting for OnKeyUp these problems would be avoided.

Upvotes: 1

Views: 2126

Answers (1)

Rachel
Rachel

Reputation: 132548

I typically use this Attached Command Behavior for hooking up Commands to Events

In your special case where you want to only execute the command when a specific key combination is pressed, I'd suggest hooking up both the KeyUp event and the KeyUp attached command.

In the regular KeyUp event, check if the key combination you want is being pressed and if not, mark the event as Handled so it doesn't get processed by the command as well

For example, this will only execute the bound command if the A key is pressed

<TextBox acb:CommandBehavior.Command="{Binding TestCommand}"
         acb:CommandBehavior.Event="KeyUp"
         KeyUp="TextBox_KeyUp"/>

and

private void TextBox_KeyUp(object sender, KeyEventArgs e)
{
    if (e.Key != Key.A)
        e.Handled = true;
}

Upvotes: 2

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