There may be many people have been more familiar with the verification control, but I have to talk about it here to help you just get started .NET newbie. Verify that the control shows the error message, can be displayed on the page, you can also pop up a messagebox, I am more preferred to pop up a MessageBox, I think it can increase the utilization of the page. Let's take a look at the specific example: Drag a few controls on WebForm: A TextBox, a Button, a RequiredFieldValidataor, a validationsummary. Setting in the properties of RequiredFieldValidateor1: Setting in the properties of Validationsummary1: Then we run: When you click the Submit button, a prompt box will appear: Look, is it very simple?
