Question

I have 2 TextBoxes (textBoxA, textBoxB), both watched by their own RequiredFieldValidator. I want to ‘enable’ the RequiredFieldValidator for textBoxB just when textBoxA has a value (or meets some specific conditions).

Use cases:

Case 1
textBoxA = “”; -> Show Required Field Validation Message
textBoxB = “”; -> Do not show validation message

Case 2
textBoxA = “has a value”;
textBoxB = “”; -> Show Required Field Validation Message

Case 3
textBoxA = “has a value”;
textBoxB = “has a value too”;

Thanks for your help!!

Answer 1

In this situation I’d use a CustomValidator for textBoxB instead of the required field validator. In the server side validation method you can control the exact nature of the validation with something like this.

if (textBoxA.Text != string.Empty)
{
    args.IsValid = textBoxB.Text != string.Empty;
}