How to allow only integers in a textbox?
asp.netasp.net Problem Overview
In my form I want to allow typing of integer values only in a textbox. How to do that?
asp.net Solutions
Solution 1 - asp.net
You can use RegularExpressionValidator for this. below is the sample code:
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:RegularExpressionValidator ID="RegularExpressionValidator1"
ControlToValidate="TextBox1" runat="server"
ErrorMessage="Only Numbers allowed"
ValidationExpression="\d+">
</asp:RegularExpressionValidator>
above TextBox only allowed integer to be entered because in RegularExpressionValidator has field called ValidationExpression, which validate the TextBox. However, you can modify as per your requirement.
You can see more example in MVC and Jquery here.
Solution 2 - asp.net
<HTML>
<HEAD>
<SCRIPT language=Javascript>
function isNumberKey(evt)
{
var charCode = (evt.which) ? evt.which : evt.keyCode;
if (charCode > 31 && (charCode < 48 || charCode > 57))
return false;
return true;
}
</SCRIPT>
</HEAD>
<BODY>
<INPUT id="txtChar" onkeypress="return isNumberKey(event)" type="text" name="txtChar">
</BODY>
</HTML>
Solution 3 - asp.net
Try this:
Note:This is using Ajax Toolkit
First add Ajax Script Manager and use the below Code
<asp:FilteredTextBoxExtender ID="TextBox1_FilteredTextBoxExtender" runat="server"
Enabled="True" TargetControlID="TextBox1" FilterType="Numbers">
</asp:FilteredTextBoxExtender>
Solution 4 - asp.net
Easy Method:-
You can use the onkeydown Property of the TextBox for limiting its value to numbers only..
Very easy..:-)
<asp:TextBox ID="TextBox1" runat="server" onkeydown = "return (!(event.keyCode>=65) && event.keyCode!=32);"></asp:TextBox>
!(keyCode>=65) check is for excludng the Albphabets..
keyCode!=32 check is for excluding the Space character inbetween the numbers..
Solution 5 - asp.net
An even easier method is to use the TextMode attribute:
<asp:TextBox runat="server" ID="txtTextBox" TextMode="Number">
Solution 6 - asp.net
try this instead
Note:This is using Ajax Toolkit
First add Ajax Script Manager and use the below Code to apply filter to the textbox
Provide the Namespace at the beginning of the asp.net page
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<asp:TextBox ID="TxtBox" runat="server"></asp:TextBox>
<cc1:FilteredTextBoxExtender ID="FilteredTextBoxExtender1" runat="server" Enabled="True" TargetControlID="TxtBox" FilterType="Numbers" FilterMode="ValidChars">
</cc1:FilteredTextBoxExtender>
Solution 7 - asp.net
You can use client-side validation:
<asp:textbox onkeydown="return (!(event.keyCode>=65) && event.keyCode!=32);" />
Solution 8 - asp.net
step by step
given you have a textbox as following,
<asp:TextBox ID="TextBox13" runat="server"
onkeypress="return functionx(event)" >
</asp:TextBox>
you create a JavaScript function like this:
<script type = "text/javascript">
function functionx(evt)
{
if (evt.charCode > 31 && (evt.charCode < 48 || evt.charCode > 57))
{
alert("Allow Only Numbers");
return false;
}
}
</script>
the first part of the if-statement excludes the ASCII control chars, the or statements exclued anything, that is not a number
Solution 9 - asp.net
Another solution is to use a RangeValidator where you set Type="Integer" like this:
<asp:RangeValidator runat="server"
id="valrNumberOfPreviousOwners"
ControlToValidate="txtNumberOfPreviousOwners"
Type="Integer"
MinimumValue="0"
MaximumValue="999"
CssClass="input-error"
ErrorMessage="Please enter a positive integer."
Display="Dynamic">
</asp:RangeValidator>
You can set reasonable values for the MinimumValue and MaximumValue attributes too.
Solution 10 - asp.net
It can be done with a compare validator as below. Unlike the other answers, this also allows negative numbers to be entered, which is valid for integer values.
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:CompareValidator ControlToValidate="TextBox1" runat="server" ErrorMessage="Integers only please" Operator="DataTypeCheck" Type="Integer" ></asp:CompareValidator>
Solution 11 - asp.net
Just use
<input type="number" id="foo" runat="server" />
It'll work on all modern browsers except IE +10. Here is a full list:
Solution 12 - asp.net
Try This :
<input type="text" onkeypress = "return isDigit(event,this.value);"/>
function isDigit(evt, txt) {
var charCode = (evt.which) ? evt.which : event.keyCode
var c = String.fromCharCode(charCode);
if (txt.indexOf(c) > 0 && charCode == 46) {
return false;
}
else if (charCode != 46 && charCode > 31 && (charCode < 48 || charCode > 57)) {
return false;
}
return true;
}
Call this function from input textbox on onkeypress event
Solution 13 - asp.net
You can use RegularExpressionValidator
<asp:TextBox ID="viewTextBox" runat="server" Text="0"></asp:TextBox>
<asp:RegularExpressionValidator ID="viewRegularExpressionValidator" runat="server" ValidationExpression="[0-9]{1,50}" ControlToValidate="viewTextBox" ErrorMessage="Please Enter numbers only">*</asp:RegularExpressionValidator>
Solution 14 - asp.net
we can use javascript code
function validateAlphaNumericCode(event) {
keyEntry = (event.which) ? event.which : event.keyCode
if (((keyEntry >= '65') && (keyEntry <= '90')) || ((keyEntry >= '97') && (keyEntry <= '122')) || (keyEntry == '37') || (keyEntry == '39') || (keyEntry == '46') || (keyEntry == '8') || (keyEntry == '9') || (keyEntry == '95') || ((keyEntry >= '48') && (keyEntry <= '57')))
return true;
else
return false;
}
validate this code with your textbox.
Solution 15 - asp.net
function CheckNumeric(event) {
var _key = (window.Event) ? event.which : event.keyCode;
if ((_key > 95 && _key < 106) || (_key > 47 && _key < 58) || _key == 8 || _key == 9 || _key == 37 || _key == 39 || _key == 190 || _key == 110) {
return true;
}
else {
return false;
}
}
<input type="text" onkeydown="return CheckNumerick(event);" />
Accept Keys: Numbers + NumPedNumbers + Tab + "," + "." + LeftButton + RightButton + Delete + BackSpace
Solution 16 - asp.net
if (document.de.your_textbox_id.value != "")
{
var checkOK = "0123456789";
var checkStr = document.de.your_textbox_id.value;
var allValid = true;
for (i = 0; i < checkStr.length; i++)
{
ch = checkStr.charAt(i);
for (j = 0; j < checkOK.length; j++)
if (ch == checkOK.charAt(j))
break;
if (j == checkOK.length)
{
allValid = false;
break;
}
}
if (!allValid)
{
alert("Please enter only numeric characters in the text box.");
document.de.your_textbox_id.focus();
}
}
Solution 17 - asp.net
You might find useful microsoft msdn article How To: Use Regular Expressions to Constrain Input in ASP.NET. Take a look at "Common Regular Expressions" Table. It has validation example for
Non- negative integer
^\d+$
This expression validates that the field contains an integer greater than zero.
Solution 18 - asp.net
User below regular expression validator.
<asp:RegularExpressionValidator ID="RegularExpressionValidatorNumeric" runat="server" ControlToValidate="yourControl ID" ErrorMessage="Registraion ID Should be a Numeric" ValidationExpression="^\d+$" ></asp:RegularExpressionValidator>
Solution 19 - asp.net
I would use ASP.NET Ajax Filter TextBoxExtender control
https://www.aspsnippets.com/Articles/ASPNet-AJAX-FilteredTextBoxExtender-Control-Example.aspx