jquery如何设置输入焦点在控件上

Question

Hey I am very new to jquery using asp.net, and I was wondering how to set focus on a textbox using jquery.

I have my script in my HeaderContent but it is not working, no focus on load. And yes I know this can be done on the server side as well, but I am just trying to get better and more familiar with jquery. Thanks.

<script type="text/javascript">
   $(document).ready(function () {
      $("#MainContent_LoginUser_UserName").focus();
   });
</script>

Answer 1

Your code is correct. If it is failing, chances are $("#MainContent_LoginUser_UserName") is not the correct selector value or perhaps jQuery is not correctly loaded.

If you are using jQuery alongside standard ASP.NET JavaScript, then the '$' will not be mapped to jQuery, but instead to ASP.NET's JavaScript framework. You may need to substitute $("#foo") for jQuery("#foo") .

Answer 2

if your MainContent_LoginUser_UserName text box is a server side control, it will not work, because the id of the control will be different, thanks to the unique id asp.net associated with your server site controllers.

Try to change to this line:

$("[id$=MainContent_LoginUser_UserName]").focus();

and check if it works!