如何将光标放在 ASP.NET 文本框的开头以获得焦点？

Question

I am fairly new to ASP, FYI. The textbox in question is for phone numbers, and I am using an Ajax MaskedEditExtender to create an input mask in the form "( ) - ___".

What is the issue now The input mask works fine, but when the user clicks into the box, the cursor just sits at whatever position they clicked at, in the middle of the input mask or wherever.

What I need I need the cursor to be automatically positioned at the beginning (first character) of the textbox when the user clicks into it. I am very familiar with how to do this in VBA using a GotFocus event. But there doesn't seem to be an event to handle this in ASP. Is there JavaScript or some kind of setting I am missing? I have searched but haven't been able to find anything to address this exactly.

I have included a link to a picture of what I am talking about, gotta earn some rep before I can embed...Thanks in advance!

Answer 1

You can set focus to your first textbox with JQuery

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
    var myFirstTextBox = $("#MyFirstTextBoxIdHere");
    $("myFirstTextBox ").focus();
});
</script>

This will autofocus on page load to your first textbox.

Answer 2

Try this out

<asp:TextBox runat="server" ID="txtMyBox" onFocus="setCursorToStart(this)"></asp:TextBox>
function setCursorToStart(x) {
        setTimeout(function() {
            x.setSelectionRange(0, 0);
        }, 0);
    }