通过Ajax发送请求时如何停止挂页

Question

I am facing a serious issue... Whenever i use Ajax to send a request and get an response my browser got hanged.. and show no loading etc...

But when i response is retrieved from the Ajax then browser and page again start working...

Below is the code that i used.....

function ShowContestStatus(contestID)
{
    $("#showContestDetails").html('<div class="loadercontest"><img src="assets/images/loading.gif">Loading Contest....</div>');

    $("#RadioGroup1_0, #RadioGroup1_1, #RadioGroup1_2").prop('disabled', true);
    $.ajax({
            url:"process/processMyContest.php",
            type:'POST',
            cache:false,
            async:false,
            data : {act : 'showcontest', cid : contestID },
            success:function(result)
            { 
                $("#showContestDetails").html(result);
                $("#RadioGroup1_0, #RadioGroup1_1, #RadioGroup1_2").prop('disabled', false);
            }
        });
    }

Please help me on this... i want to get the same response as on other websites when you send a request and they are using ajax the page neither hanged and also each processing like scrolling etc is visible ......

So please suggest me good ideas.... so i can get rid of it and make my ajax smooth for page without effecting and irritate the other person by hanged...

Thanks in advance...:)

Answer 1

The problem is async:false ... Since your ajax request is synchronous the script execution will wait for the request to complete to continue..

Since browser uses a single threaded execution pattern(either it will execute script or repaint or wait for user events at a time- not all at the same time), your browser tab will stop listening to user(so it will look like it is hanged)

function ShowContestStatus(contestID) {
    $("#showContestDetails").html('<div class="loadercontest"><img src="assets/images/loading.gif">Loading Contest....</div>');

    $("#RadioGroup1_0, #RadioGroup1_1, #RadioGroup1_2").prop('disabled', true);
    $.ajax({
        url: "process/processMyContest.php",
        type: 'POST',
        cache: false,
        //remove async: false,
        data: {
            act: 'showcontest',
            cid: contestID
        },
        success: function (result) {
            $("#showContestDetails").html(result);
            $("#RadioGroup1_0, #RadioGroup1_1, #RadioGroup1_2").prop('disabled', false);
        }
    });
}

Ajax.async

By default, all requests are sent asynchronously (ie this is set to true by default). If you need synchronous requests, set this option to false. Cross-domain requests and dataType: "jsonp" requests do not support synchronous operation. Note that synchronous requests may temporarily lock the browser, disabling any actions while the request is active . As of jQuery 1.8, the use of async: false with jqXHR ($.Deferred) is deprecated; you must use the success/error/complete callback options instead of the corresponding methods of the jqXHR object such as jqXHR.done() or the deprecated jqXHR.success().

Answer 2

将async：true设为使浏览器在运行ajax代码时侦听其他事件。