Overrite shift behavior in NumericUpDown - winforms

Question

Per user request I implemented NumericUpDown with varying Increment (0.1 on arrow press, 0.01 on SHIFT+arrow press) as suggested in this answer. It works very well when the user interacts with the mouse to press the control's arrows.
However, the keyboard input with the Up arrow does not trigger UpButton() when the SHIFT is pressed (same for the Down key and the DownButton()). Instead, the text in the control is being selected. Since the normal behavior is for both methods to be triggered when the keyboard arrows are pressed, of course I would like to keep this functionality on for the SHIFT combination as well.
So far I have tried overriding every method in the NumericUpDown which contains the "Key" word but none could help me. ProcessCmdKey can detect the key combination and disable the default selection behavior but it doesn't not lead to UpButton/DownButton being triggered either.
Any ideas?

Answer 1

Shift + Up/Down are text selection shortcut keystrokes for the textbox portion of the NumericUpdate. Just as they are for a regular TextBox. Disabling this feature isn't the greatest idea.
Multiple ways to do this, perhaps the easiest is to detect the keystroke in an override for the form's ProcessCmdKey() method. So they'll work on any NUD and the code changes are small. I'll post the C# version of it, creating a winforms app in C++/CLI is too much of a hassle these days:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
var ctl = this.ActiveControl as NumericUpDown;
if (ctl != null) {
if (keyData == (Keys.Up | Keys.Shift)) {
ctl.Value = Math.Min(ctl.Maximum, ctl.Value + 10 * ctl.Increment);
return true;
}
if (keyData == (Keys.Down | Keys.Shift)) {
ctl.Value = Math.Max(ctl.Minimum, ctl.Value - 10 * ctl.Increment);
return true;
}
}
return base.ProcessCmdKey(ref msg, keyData);
}