Build Your Own ASP.NET 2.0 Web Site Using C# & VB, Second Edition

Using Validation Controls

Now that you have an understanding of what validation controls can do, let’s

have a look at the different controls that are available in ASP.NET:

❑

RequiredFieldValidator

❑

RangeValidator

❑

RegularExpressionValidator

❑

CompareValidator

❑

CustomValidator

❑

ValidationSummary

If you’re working with Visual Web Developer, you can see the validation controls

in the Validation tab of the Toolbox, as Figure 6.4 illustrates.

Figure 6.4. Accessing the validation controls in Visual Web

Developer

Validation controls are a particular kind of web server control, and are inserted

as tags with the asp: prefix. Once a validation control is inserted, it validates an

existing control elsewhere on the page, and presents an error message to the user

if necessary. To validate a field, all you have to do is insert a control—there’s no

229

Using Validation Controls