NumLock isKeyLocked not working

Question

I'm using the following code to check is NumLock, CapsLock or Insert are pressed, and if their status is ON update a label's text accordingly. But for some reason I can't get NumLock to work properly. It updates the label's text with "Num" if NumLock is set on but fails to update if NumLock is set off. Every other check in the code works. Would appreciate any help. Thank you.

        private void num_ins_caps_keyDown(object sender, KeyEventArgs e)
    {
        if ((e.KeyCode & Keys.KeyCode) == Keys.CapsLock)
        {
            if (Control.IsKeyLocked(Keys.CapsLock))

                num_ins_caps1.capsLabel.Text = "Caps";
            else
                num_ins_caps1.capsLabel.Text = null;
        }

        if ((e.KeyCode & Keys.KeyCode) == Keys.NumLock)
        {
            if (Control.IsKeyLocked(Keys.NumLock))

                num_ins_caps1.numLabel.Text = "Num";
            else
                num_ins_caps1.numLabel.Text = null;
        }

        if ((e.KeyCode & Keys.KeyCode) == Keys.Insert)
        {
            if (Control.IsKeyLocked(Keys.Insert))

                num_ins_caps1.insLabel.Text = "Ins";
            else
                num_ins_caps1.insLabel.Text = null;
        }
    }

The standard scourge of KeyDown. Override ProcessCmdKey() instead. — Hans Passant, Dec 10 '13 at 23:44

Grant Winney · Answer 1 · 2013-12-10T23:33:52.997

I'm not sure where you're calling this from, but if you're using some control's KeyDown event, try the KeyUp event instead.

I tested your code and experienced the same issue. I don't know why it doesn't work with KeyDown, but it worked as expected when I attached it to the KeyUp event.

I'm assuming that the signal from Numlock turning "on" is sent before the KeyDown event fires, but the signal from Numlock turning "off" is sent after the KeyDown event fires, so the code executes and still thinks it's enabled. There's nothing in the msdn docs to explain the behavior.

NumLock isKeyLocked not working

1 Answers1