How do I use validation controls in ASP.NET?

How do I use validation controls in ASP.NET?

In ASP.NET, validation controls are used to ensure that user input is valid before processing it. You can use controls like RequiredFieldValidator, RangeValidator, and RegularExpressionValidator to enforce rules on user inputs.

Can you give me an example of a RequiredFieldValidator?

Sure! To use a RequiredFieldValidator, you would add it to your ASP.NET page like this: <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="TextBox1" ErrorMessage="This field is required." ForeColor="Red" />.

What happens if the validation fails?

If validation fails, the error message specified in the validation control will be displayed, and the form will not be submitted until the user corrects the input.

Can I customize the error messages?

Yes, you can customize the error messages by setting the ErrorMessage property of the validation control to any string you want.