How can I allow only numeric value into textbox field in C#.Net and ASP,Net 2?

Hello


I want to allow only numeric field to be entred into textbox. How can I do that in C#.Net2,ASP.Net2 or Javascript.





thanks

How can I allow only numeric value into textbox field in C#.Net and ASP,Net 2?
%26lt;script language="javascript"%26gt;


function maskBox(e)


{


var keynum = null;


if(window.event)


{


keynum = e.keyCode;


}


else if(e.which)


{


keynum = e.which;


}


if(keynum)


{


if(keynum==8 || keynum==9)


{


return true;


}


else


{


return isInt(String _


.fromCharCode(keynum));


}


}


}





function isInt(test)


{


var ints = "0123456789";


if(ints.indexOf(test)%26gt;-1)


{


return true;


}


return false;


}


%26lt;/script%26gt;





In your code, simply write:





txtTextBoxId.Attributes _


.Add("onKeyDown", _


"return maskBox(event);")





This will work in IE, FF, Opera, and most others. For the few that don't understand it, it will just let them type anything; won't return an error. Sorry for the line breaks, Yahoo seems to be hiding code if I don't break it up.
Reply:You can do it easily via asp or javascript.


Just you need the ASCII code of a key.


So you can get them via textpad.Textpad has all of them on the left side panel.


Find the key code(number) from 0 to 9.


Then you should write some code for Text_Changed event of the textbox.Just you should unhandle the key press function while a number is not entered.





If(e.KeyCode%26lt;num1 | e.KeyCode%26gt;num2)


{


e.Handled=false;


}
Reply:The easiest way is to use a Range Validator control.





%26lt;asp:TextBox ID="txtTest" runat="server" /%26gt;


%26lt;asp:RangeValidator ID="ValidateTest" runat="server" ControlToValidate="txtTest" Type="Integer" ErrorMessage="Input should be integer" MaximumValue="1000" MinimumValue="0" /%26gt;





Notice: In order to make the field required, you have to add a Required Field validator. i.e. the code above considers that an empty textbox has valid data.





Hope this helps
Reply:In VB, you can use the KEYPRESS event of the textbox to restrict the ASCII characters to between certain values. Not quite sure how to do that in C#, but that should give you a startign point.
Reply:You validate the text using a regular expression.


I believe the regex for non-numeric is \D .





So any match for \D means there is non-numeric in the string.