Question

I have scenario, Page contains Check in date and Check out date for input. I used user control for datepicker, so both dates are called same user control.
Like,

Check In Date: <uc:datepicker ID="CheckInDate" runat="server" />
Check Out Date: <uc:datepicker ID="CheckOutDate" runat="server" />

Now I do validation for both dates which should not be blank like.

public class CustomiseDatePickerValidator : BaseValidator
 {

   protected override bool EvaluateIsValid()
        {
            Control c = this.FindControl(this.ControlToValidate);
            DatePicker datepickerSelected = c as DatePicker;
            ICustomiseRadDatePicker additionUserControl =    (ICustomiseRadDatePicker)c.Parent;

            if (string.IsNullOrEmpty(datepickerSelected.DateInput.Text))
             {
                return false;
             }

            return true;
        }
 }

This is working fine but I want also compare both datepicker value So Check in date Should be less than Check out date

Answer 1

It would probably be easier to use a CustomValidator for this. With the CustomValidator, you can specify your own client-side validation logic.

See this question for more details:
ASP.NET Custom Validator Client side & Server Side validation not firing