Allow backspace

[Guest]

In a text box I want to allow only numbers and backspace.

Currently the code I have only allows numbers. How do I also allow backspace?

if (!Char.IsDigit(e.KeyChar))
{
e.Handled = true;
}

 

[Peter Rilling]

Put a breakpoint there and see what character code you get when you hit
backspace. It should be one of the control characters.

 

[Mythran]

In a text box I want to allow only numbers and backspace.

Currently the code I have only allows numbers. How do I also allow
backspace?

if (!Char.IsDigit(e.KeyChar))
{
e.Handled = true;
}

if (!Char.IsDigit(e.KeyChar) && e.KeyCode != Keys.Back) {
e.Handled = True;
}

HTH,
Mythran

 

[Morten Wennevik]

Hi Mike,

I usually use Char.IsControl as this allows for cut and paste as well.

if (!Char.IsDigit(e.KeyChar) || !Char.IsControl(e.KeyChar))
e.Handled = true;