Data validation is most important for data driven applications. This article talks about the basics of validation in Silverlight 4.
Following are some screen shots of how the sample application looks before and after the validation.
Following is an employee class which has two properties namely name and age. The properties of the employee class are validated whenever the user sets the properties. In this example, the following checks are made
For Name property : Name should not be empty and should contain only letters ("alphabets")
For Age property : Age should be between 0 - 100
Following is the mainpage.xaml where you have to set the validation for the controls.
For textbox control accepting Name of employee
For textbox control accepting Age of employee