How to set RequiredFieldValidator on DropDownList in ASP.NET?

Lets assume that we have a DropDownList named 'Gender' in our Registration Form and it is a required field so that user must select it. First we have to set the following DropDownList properties:

ID	Gender
Items	(Collection)...

• Click on the Collection button then ListItem Collection Editor would be open as shown below:

• Click on the Add button and set the ListItem properties as follows:

 

• Click 'OK' and set the RequiredFieldValidator properties as follows:

ID	Gender_Validator
ControlToValidate	Gender
ErrorMessage	Please select Gender
InitialValue	0

Now if user does not select either 'Male' or 'Female' then RequiredFieldValidator would generate an error message.

Code Snippet:

<asp:RequiredFieldValidator ID="Gender_Validator" runat="server" ControlToValidate="Gender" ErrorMessage="Please Select Gender" InitialValue="0"></asp:RequiredFieldValidator>

Demo:

Gender	Select Male Female	Please select your Gender

Download Source Code