Here, we will see how to check number of
character has been inserted in the TextBox. A TextBox Which has max length 120
character and we insert a character in TextBox max length will be display 119
characters. When We enter 120 characters in the TextBox that will be the Max
length.
Drag and drop a TextBox on the page. Select
TextBox and press F4 to property window.
TextMode="MultiLine"
Now add the following code in the Head section
of the .aspx page.
|
<head
runat="server">
<title></title>
<style
type="text/css">
.valid
{
background-color:
#FFFFFF;
color:
#000000;
}
.invalid
{
background-color:
#FFCCCC;
color:
#ff0000;
}
</style>
<script
language="javascript">
function textCounter1(field, maxlimit)
{
if (field.value.length > maxlimit) {
field.value = field.value.substring(0, maxlimit);
document.getElementById('message').className
= "invalid";
document.getElementById('message').focus();
//alert('You have reached your maximum
character limit.');
}
else {
document.getElementById('message').className
= "valid";
}
}
function textCounter(field,
countfield, maxlimit) {
if (field.value.length > maxlimit)
// if too long...trim it!
field.value = field.value.substring(0, maxlimit);
else
countfield.value = maxlimit - field.value.length;
}
</script>
</head> |
Now add the following code in the body section.
|
<body
bgcolor="#FFFFFF">
<form
name="blah"
action=""
method="post"
runat="server">
<asp:TextBox
ID="message"
runat="server"
name="message"
onkeydown="textCounter(this.form.message,this.form.remLen,120)"
onkeyup="textCounter1(this.form.message,
120)" class="validentry"
Height="101px"
TextMode="MultiLine"
Width="228px"></asp:TextBox>
<br
/>
<input
readonly type="text"
name="remLen"
size="3"
maxlength="3"
value="120"
position:
absolute;
style="width:
34px">Character left<br
/>
<br
/>
<br
/>
</form>
</body> |
Now run the application and
check number of character has been inserted in the
TextBox.
![text1.gif]()
Figure1
Now Insert max length characters in TextBox.
![text2.gif]()
Figure2