Chapter 3. Using the Validation Controls

In this Chapter

Overview of the Validation Controls

Using the RequiredFieldValidator Control

Using the RangeValidator Control

Using the CompareValidator Control

Using the RegularExpressionValidator Control

Using the CustomValidator Control

Using the ValidationSummary Control

Creating Custom Validation Controls

Summary

In this chapter, you learn how to validate form fields when a form is submitted to the web server. You can use the validation controls to prevent users from submitting the wrong type of data into a database table. For example, you can use validation controls to prevent a user from submitting the value "Apple" for a birth date field.

In the first part of this chapter, you are provided with an overview of the standard validation controls included in the ASP.NET 2.0 Framework. You learn how to control how validation errors are displayed, how to highlight validation error messages, and how to use validation groups. You are provided with sample code for using each of the standard validation controls.

Next, we extend the basic validation controls with our own custom validation controls. For example, you learn how to create an AjaxValidator control that enables you to call a server-side validation function from the client.