How can I force input to uppercase in an ASP.NET textbox?

Why not use a combination of the CSS and backend? Use:

style='text-transform:uppercase' 

on the TextBox, and in your codebehind use:

Textbox.Value.ToUpper();

You can also easily change your regex on the validator to use lowercase and uppercase letters. That's probably the easier solution than forcing uppercase on them.


Use a CSS style on the text box. Your CSS should be something like this:

.uppercase
{
    text-transform: uppercase;
}

<asp:TextBox ID="TextBox1" runat="server" Text="" CssClass="uppercase"></asp:TextBox>;