Tab key and keydown, keyup event

I saw a problem in the forum today, so I studied it carefully. The problem is about the tab key, keydown, and keyup events!

For example, if you have a Textbox Control and press tab in the case of focus, the keydown event is not triggered, but the input focus is directly removed! In other words, the tab key cannot be captured:

Private void textbox1_keydown (Object sender, keyeventargs E)
{
E. Handled = true;
Textbox2.text = E. keyValue. tostring ("X ");
}

But it is interesting that this key can trigger the keyup event that receives the focus. For example, you press the tab key in textbox1 and then textbox2 gets the input focus, you can capture this key in the keyup event of textbox2:
Private void textbox2_keyup (Object sender, keyeventargs E)
{

This. textbox2.text = E. keyValue. tostring ("X ");

}

You can try it!