在ASP.NET中使用RequiredFieldValidator的DropdownList值

Question

How to select any specific value from dropdownlist. Currently have YES and NO . If No is selected then should show an error message using Required Field Validator. There should be no error message when the value is selected as YES from dropdown

Answer 1

You can set the InitialValue of the RequiredFieldValidator to NO (if the value is the same as the text, otherwise use the appropriate value):

<asp:asp:RequiredFieldValidator ID="ReqYesNo" runat="server" 
    ControlToValidate="DropDownListYesNo"
    InitialValue="NO">
</asp:RequiredFieldValidator>

Answer 2

add the value on which you want to show error message in InitialValue property of required field.

like this -

<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="you have selected NO" ControlToValidate="YOURDropDownID" InitialValue="NO"></asp:RequiredFieldValidator>