Specifying maxlength for multiline textbox

Question

I\'m trying to use asp:

I want a way to spe

Answer 1

Nearly all modern browsers now support the use of the maxlength attribute for textarea elements.(https://caniuse.com/#feat=maxlength)

To include the maxlength attribute on a multiline TextBox, you can simply modify the Attributes collection in the code behind like so:

txtTextBox.Attributes["maxlength"] = "100";

If you don't want to have to use the code behind to specify that, you can just create a custom control that derives from TextBox:

public class Textarea : TextBox
{
    public override TextBoxMode TextMode
    {
        get { return TextBoxMode.MultiLine; }
        set { }
    }

    protected override void OnPreRender(EventArgs e)
    {
        if (TextMode == TextBoxMode.MultiLine && MaxLength != 0)
        {
            Attributes["maxlength"] = MaxLength.ToString();
        }

        base.OnPreRender(e);
    }
}