#1,076 – Two Ways to Check for Use of Modifier Keys in Keypress Handlers

You can check for the presence of modifier keys (e.g. Alt, Ctrl, Shift, or Windows key) in keypress handlers using the KeyboardDevice.Modifier property.  For example:

        private void Window_KeyDown(object sender, KeyEventArgs e)
        {
            if ((e.Key == Key.G) &&
                (e.KeyboardDevice.Modifiers == ModifierKeys.Control))
                MessageBox.Show("Ctrl+G detected");
        }

Note that this method doesn’t distinguish between whether you pressed the left vs. right Ctrl keys.  This is normally what you want.  If you do want to distinguish between the two, you can explicitly check for left vs. right.

        private void Window_KeyDown(object sender, KeyEventArgs e)
        {
            if ((e.Key == Key.G) &&
                (Keyboard.IsKeyDown(Key.LeftCtrl)))
                MessageBox.Show("Left Ctrl+G detected");
            else if ((e.Key == Key.G) &&
                (Keyboard.IsKeyDown(Key.RightCtrl)))
                MessageBox.Show("Right Ctrl+G detected");
        }