How to set maxlength for multiline TextBox

asp.nettextbox

When using a MultiLine TextBox (which generates a TextArea) setting the MaxLength property has no effect. What is the best workaround? I'd like to get basic, intended functionality with minimum of ugly javascript etc. Just prevent user from entering more than max number of characters.

Best Solution

If you don't care about older browsers (see supported browsers here),
you can set MaxLength normally like this

<asp:TextBox ID="txt1" runat="server" TextMode="MultiLine" MaxLength="100" />

and force it to be printed out to the HTML

protected void Page_Load(object sender, EventArgs e)
{
  if (!IsPostBack)
    txt1.Attributes.Add("maxlength", txt1.MaxLength.ToString());
}