System.Web.UI.WebControls Namespace

Makes the associated input control a required field.

Use this control to make an input control a required field. The input control fails validation if the value of the associated input control is no different from the InitialValue property upon losing focus.

Multiple validators can be associated with the same input control. For example, a RequiredFieldValidator can be used to ensure input to a control, while at the same time a RangeValidator can be used to ensure that the input is within a specified data range.

For examples illustrating use of this control, see the individual member types of this class. For syntax information, see RequiredFieldValidator in ASP.NET Syntax for Validation Controls.

BaseValidator Class   Validating Required Entries