c# - Input handling in WinForm

Question

What is the best way to block certain input keys from being used in a TextBox with out blocking special keystrokes such as Ctrl-V/Ctrl-C?

For example, only allowing the user to enter a subset of characters or numerics such as A or B or C and nothing else.

Answer 1

I used the Masked Textbox control for winforms. There's a longer explanation about it here. Essentially, it disallows input that doesn't match the criteria for the field. If you didn't want people to type in anything but numbers, it simply would not allow them to type anything but numbers.