ASP.NET TextBox.MultiLine maxlength
Posted by maheshsingh21 on December 28, 2007
ASP.NET TextBox.MultiLine maxlength
According to msdn in ASP.NET you can not use textbox’s MaxLength property with Multiline Mode. But I was required in my current application. So I search google and other search engines and finally got few solution. I am simply compiling all of the solutions in single post.
Solution Number 1 for
ASP.NET TextBox.MultiLine maxlength
Add following javascript
function Count(text,long)
{
var maxlength = new Number(long); // Change number to your max length.
if(document.getElementById(‘<%=textBox.ClientID%>’).value.length > maxlength){
text.value = text.value.substring(0,maxlength);
alert(” Only “ + long + ” chars”);
}
Where “textBox” is the asp text box ID.
Also add following events in your textbox.
onKeyUp=”javascript:Count(this,200);” onChange=”javascript:Count(this,200);”
Your textbox code should look like
<asp:TextBox ID=”textBox” onKeyUp=”javascript:Count(this,2);” onChange=”javascript:Count(this,2);” TextMode=MultiLine Columns=”5″ Rows=”5″ runat=server>
</asp:TextBox>
Solution Number 2 for
ASP.NET TextBox.MultiLine maxlength
Another way to achieve this is regular expression. You can add following regular expression validate on asp text box.
<asp:RegularExpressionValidator ID=”txtConclusionValidator1″ ControlToValidate=”textBox” Text=”Exceeding 200 characters” ValidationExpression=”^[\s\S]{0,2}$” runat=”server” />
Hope this helps you!!!
