How to make DataGridView's cell format to "00:00:00" and Button Shortcut

[soclose]

Hi All,

1) I'd like to make DataGridView's Cell Format to "00:00:00". When deleting all, its format is canceled, i mean we need to type this ":" again ourself. I don't like that. Is there any like MaskTextBox "##:##:##" in DataGridView? Or how to make this format in column's cell? I assign this cell to DateTime.

2) I get not displaying Button Shortcut at runtime. I mean, I typed Button's Text property "&Add" but at runtime, system not shown "Add"

Pls share to me.