How Can I Force Input To Uppercase In An ASP.NET Textbox?

I'm writing an ASP.NET application. I have a textbox on a webform, and I want to force whatever the user types to upper case. I'd like to do this on the front end. You should also

Solution 1:

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.

Solution 2:

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>;

Solution 3:

Okay, after testing, here is a better, cleaner solution.

$('#FirstName').bind('keyup', function () {

    // Get the current value of the contents within the text box
    var val = $('#FirstName').val().toUpperCase();

    // Reset the current value to the Upper Case Value
    $('#FirstName').val(val);

});

Solution 4:

**I would do like:
<asp:TextBox ID="txtName" onkeyup="this.value=this.value.toUpperCase()" runat="server"></asp:TextBox>**

Solution 5:

You can intercept the key press events, cancel the lowercase ones, and append their uppercase versions to the input:

window.onload = function () {
    var input = document.getElementById("test");

    input.onkeypress = function () {
        // So that things work both on Firefox and Internet Explorer.
        var evt = arguments[0] || event;
        var char = String.fromCharCode(evt.which || evt.keyCode);

        // Is it a lowercase character?
        if (/[a-z]/.test(char)) {
            // Append its uppercase version
            input.value += char.toUpperCase();

            // Cancel the original event
            evt.cancelBubble = true;
            return false;
        }
    }
};

This works in both Firefox and Internet Explorer. You can see it in action here.