In asp.net, I need to add validator to textbox that forces the input to be numbers

Question

In asp.net, I need to add a validator to a textbox that forces the input to be numbers.

Is this built in?

I have already added a required field validator to the textbox.

Answer 1

You could use a Regex Validator to ensure the text is numeric

I think the regex would be

[0-9]*

e.g.

<asp:TextBox ID="tbxNumbers" runat="server" />
<asp:RegularExpressionValidator ID="revNumericValidator" runat="server" 
                ValidationExpression="^[0-9]*$" ControlToValidate="tbxNumbers" ErrorMessage="Must be Numeric" />

EDIT: As the other two posters also pointed out you can also use \d to represent a Numeric Character

Answer 2

<asp:RegularExpressionValidator runat="server"
            ControlToValidate="numbersOnlyTextBox" 
            ErrorMessage="Enter only numeric characters." 
            ValidationExpression="^\\d+$" />

Answer 3

Use a range validator.

<asp:TextBox ID="MyTextBox" MaxLength="4" Width="75" 
   Text="0" runat="server"></asp:TextBox>
<asp:RangeValidator ID="MyRangeValidator"  Display="Static" Type="Integer"
   MaximumValue="9999" MinimumValue="0" EnableClientScript="true" 
   ControlToValidate="MyTextBox" runat="server" SetFocusOnError="true" 
   ErrorMessage="Ooops"></asp:RangeValidator>

This permits you to use numbers with decimal places (by using Type="Double" or "Currency"), or other kinds of numbers that Windows recognizes.

Check MSDN for more info on the Range Validator Control.

Answer 4

I think there needs to be more clarification of the requirements here. What kind of numbers are we talking about? Positive integers? Any integer? A number with a decimal place? What about commas in the number (1,000)?

I recommend a RegularExpressionValidator to do your work, but these questions make a difference when it comes to which RegEx you use.