如何在ASP.NET中触发自定义验证器事件？

Question

I am using custom validator tool in asp.net to check whether a text box is blank or not(I did not use requiredfieldvalidator because the text box in question is going to be enabled occasionally).The problem is that the custom validator event in code behind is not firing at all.This is the source code:

<asp:TextBox ID="txtS_rentSDate" runat="server" Font-Names="Bookman Old Style" 
                Font-Size="Medium" Width="326px" 
                ontextchanged="txtS_rentSDate_TextChanged" 
                CausesValidation="True"></asp:TextBox>    

<asp:CustomValidator ID="cvRentSDate" runat="server" 
                ControlToValidate="txtS_rentSDate" 
                ErrorMessage="Please enter the rent start date" 
                onservervalidate="cvRentSDate_ServerValidate" ValidateEmptyText="True" 
                Width="180px"></asp:CustomValidator>

Code behind:

protected void cvRentSDate_ServerValidate(object source, ServerValidateEventArgs args)
{
    args.IsValid = (args.Value.Length > 0);
}

Kindly let me know where I am going wrong and what is the proper way to do it?

Answer 1

<asp:CustomValidator ID="cvRentSDate" runat="server" 
            ControlToValidate="txtS_rentSDate" 
            ErrorMessage="Please enter the rent start date" 
            OnServerValidate="cvRentSDate_ServerValidate" ValidateEmptyText="True" 
            Width="180px"></asp:CustomValidator>

Try with my above lines. May be you need to use OnServerValidate instead of onservervalidate.