WPF: How to detect Key repetition, in Key* events?

Question

NOTE: e.IsRepeat is confirmed to work. The problem exists because I use Remote Desktop from Ubuntu to Windows.

I found a workaround for this Remote Desktop problem:

1. Disable key repetition in Ubuntu.
2. In host Windows: Enable FilterKeys with "Turn on Repeat Keys and Slow Keys"
3. Using regedit go to HKEY_CURRENT_USER\Control Panel\Accessibility\Keyboard Response
   1. Set AutoRepeatDelay, AutoRepeatRate, and Last Valid Delay, Last Valid Repeat to small enough.
   2. Disable FilterKeys and re-enable to refresh the registry changes.

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How does one detect key repetition in KeyUp/KeyDown (or PreviewKeyDown/PreviewKeyUp) events?

I have following test case:

    public Window1() {
        InitializeComponent();

        this.KeyDown += new KeyEventHandler(Window1_KeyDown);
        this.KeyUp += new KeyEventHandler(Window1_KeyUp);
    }

    void Window1_KeyUp(object sender, KeyEventArgs e) {
        if (e.Key == Key.D) {
            Console.WriteLine("DOWN: key: {0}, rep{1}, togg{2}, dow{3}, up{4}", e.Key, e.IsRepeat, e.IsToggled, e.IsDown, e.IsUp);
        }
    }

    void Window1_KeyDown(object sender, KeyEventArgs e) {
        if (e.Key == Key.D) {
            Console.WriteLine("UP: key: {0}, rep{1}, togg{2}, dow{3}, up{4}", e.Key, e.IsRepeat, e.IsToggled, e.IsDown, e.IsUp);
        }
    }

It gives me to Output screen following if I press letter D down and release it after a while:

// Note: Here I press D-key down.
UP: key: D, repFalse, toggTrue, dowTrue, upFalse
DOWN: key: D, repFalse, toggTrue, dowFalse, upTrue
UP: key: D, repFalse, toggFalse, dowTrue, upFalse
DOWN: key: D, repFalse, toggFalse, dowFalse, upTrue
UP: key: D, repFalse, toggTrue, dowTrue, upFalse
DOWN: key: D, repFalse, toggTrue, dowFalse, upTrue
UP: key: D, repFalse, toggFalse, dowTrue, upFalse
DOWN: key: D, repFalse, toggFalse, dowFalse, upTrue
UP: key: D, repFalse, toggTrue, dowTrue, upFalse
DOWN: key: D, repFalse, toggTrue, dowFalse, upTrue
UP: key: D, repFalse, toggFalse, dowTrue, upFalse
DOWN: key: D, repFalse, toggFalse, dowFalse, upTrue
UP: key: D, repFalse, toggTrue, dowTrue, upFalse
DOWN: key: D, repFalse, toggTrue, dowFalse, upTrue
UP: key: D, repFalse, toggFalse, dowTrue, upFalse
DOWN: key: D, repFalse, toggFalse, dowFalse, upTrue
UP: key: D, repFalse, toggTrue, dowTrue, upFalse
DOWN: key: D, repFalse, toggTrue, dowFalse, upTrue
UP: key: D, repFalse, toggFalse, dowTrue, upFalse
DOWN: key: D, repFalse, toggFalse, dowFalse, upTrue
UP: key: D, repFalse, toggTrue, dowTrue, upFalse
DOWN: key: D, repFalse, toggTrue, dowFalse, upTrue
UP: key: D, repFalse, toggFalse, dowTrue, upFalse
DOWN: key: D, repFalse, toggFalse, dowFalse, upTrue
// Note: Here I release D-key.

Apparently the e.IsRepeat is always false, so that is useless. I also noticed that sometimes the first event is also toggFalse, dowTrue, so that cannot be used as a pattern.

I also note that clever way of using timing can be used to detect repetition, but there must be a native way to do this.

Answer 1

Set a variable when the keydown event fires tracking which key is pressed, do your thing(tm) then ignore further events for that key. When keyup fires clear the variable. You may need a list to track multiple keys.