Question

Good afternoon,

I need help to solve the following problem:

I need to restrict a range of values to a textbox.
I have already the minimum and maximum value allowed in the textbox, but is missing me intermediate values.

An example:

From the minimum value -2,00 to maximum value 0,00 it accepts: -2,00 | -1,75 | -1,50 | -1,25 | -1,00 | -0,75 | -0,5 | -0,25 | 0,00

From the minimum value 0,00 to maximum value 1,00 it accepts: 0,00 | 0,25 | 0,50 | 0,75 | 1,00

and so on..

What will be the best way to do that?

Thank you.

Answer 1

You could use a CustomValidator and write your own validation method to check if the value is a multiple of 0.25. You can add this to the page:

<asp:CustomValidator 
    ID="NumericInputValidator" 
    ControlToValidate="NumericInput"
    Display="Dynamic"
    runat="server" 
    OnServerValidate="ValidateNumericInput" 
    ErrorMessage="The given input must be a numberic value and it must be a multiple of 0.25" />

And then add something like this to the code behind:

protected void ValidateNumericInput(object sender, ServerValidateEventArgs args)
{
    decimal value;
    IFormatProvider formatProvider = CultureInfo.CurrentCulture; // Change this to the desired culture settings.
    bool isNumber = decimal.TryParse(args.Value, NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign, formatProvider, out value);

    // The number must be a multiple of 0.25, so when multiplied by 4, it should be an integer.
    args.IsValid = isNumber && decimal.Truncate(value * 4) == value * 4;
}