Hi,

I would like to extend the TextBox so that I can enter numeric only values. How can I extend the CharacterCasing property to include a new'numeric' enum?

BTW I am using C# in VS2005

Regards

Ron.

Hi Ron,

You cannot add another value to the CharacterCasing enumeration because you don't have the source for it. Instead, you could extend TextBox and add your own property that controls the allowed input.

Also, you might try searching for existing implementations. I'm quite sure this problem would have been solved many times over.

HTH,
Kent

add the textbox KeyPress event and paste this code in it:
if (!char.IsNumber(e.KeyChar))

As people have often mentioned, handling KeyPress event is not foolproof. Someone can copy-paste text into the textbox and this logic will fail.

I usually handle the Leave event.

TextBox_Leave()
{
}

I see two advantages:

1. The event is not triggered every time the user enters a character.
2. It works for any kind of input device - keyboard or mouse.

I see one major problem with this, though:

If your form has its AcceptButton set to any button, and the user presses "Enter" after entering some text into the TextBox, the Leave event is never triggered and the form is closed. Either you can disable the AcceptButton (if you have many text boxes to validate) or validate the text again in 'Form_Closing' event.

This solution has worked well for me until now.

Thanks for the suggestions with regards to the actual logic, but my main problem is how to extend the TextBox CharacterCasing property, so that the code can determine what type of characters are t obe allowed, e.g. numerics or upper/lower/normal text?

Regards

Ron.

what do you mean by this? if not what i posted erlier? please give an example.

Hi Ron,

You cannot add another value to the CharacterCasing enumeration because you don't have the source for it. Instead, you could extend TextBox and add your own property that controls the allowed input.

Also, you might try searching for existing implementations. I'm quite sure this problem would have been solved many times over.

HTH,
Kent

Hi Kent,

Thanks for that. It is sort of what I figured, but I was still hoping as it does seem to be somewhat of an oversight, as this facility has always been available in the previous MS development products that I have used in the past :-(

Thanks again.

Ron.