Question

I placed a label that named as LabelTotalNumber on Asp.net webform. I want update a value every one minute by jQuery without refresh the form. How do I do it?

I can do this way in Page_Load event for one time.

var sqlResult = (From obj in db.RequestList
                 where obj.IsApproved == "Approved"
                 select obj).count();
LabelTotalNumber.text = sqlResult;

Answer 1

Out-of-the-Microsoft-box you could use an UpdatePanel and a Timer.

If you don’t like the contents of the Microsoft box and wanna use jQuery/javascript you could send AJAX requests at regular intervals (using the window.setInterval method) to an ASP.NET PageMethod (in which case basically you will have to give yourself a little pain to read jQuery’s documentation/tutorials and write a little code).

So an ASP.NET PageMethod:

[WebMethod]
public static int Approved()
{
    return (from obj in db.RequestList
            where obj.IsApproved == "Approved"
            select obj).Count();
}

and then hammer this PageMethod with an AJAX request every minute or so:

window.setInterval(function() {
    $.ajax({
        url: '/foo.aspx/Approved',
        type: 'POST',
        contentType: 'application/json',
        data: '{ }',
        success: function(result) {
            var count = result.d;
            // TODO: do something with the count returned by the server
            // like assigning it to a label or something:
            $('#someLabelId').html(count);
        }
    });
}, 60 * 1000);