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ajax async 异步 请求 响应

ajax异步特性的示例

鹭岛小千 鹭岛小千 发表于2021-12-26 17:29:42 浏览384 评论0

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支持异步(async)请求是ajax的重要特性。

示例的文件结构如下:

62-1.png

client.html源码:

<!DOCTYPE html>
<head>
    <title>ajax_async_demo_by_xqoffice</title>
    <style>
        p,div {border: 1px solid gray;width: 100px;}
        button {margin-top: 18px;}
    </style>
    <script type="text/javascript" src="jquery.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
            $('button').click(function(){
                $.ajax({
                    "type":"POST",
                    "url":"server.php",
                    "data":"id=1&var2=val2",
                    "beforeSend":function(){
                        $('#p1').html('<img src="icon/running.gif" />');
                    },
                    "success":function(backdata){
                        $('#p1').html('<img src="icon/done.png" />');
                        $('#div1').html(backdata);
                    },
                    "error":function(){
                        $('#p1').html('<img src="icon/error.png" />');
                    }
                });
                $.ajax({
                    "type":"POST",
                    "url":"server.php",
                    "data":"id=2&var2=val2",
                    "beforeSend":function(){
                        $('#p2').html('<img src="icon/running.gif" />');
                    },
                    "success":function(backdata){
                        $('#p2').html('<img src="icon/done.png" />');
                        $('#div2').html(backdata);
                    },
                    "error":function(){
                        $('#p2').html('<img src="icon/error.png" />');
                    }
                });
            });
        });
    </script>
</head>
<body>
    <p id='p1'>p1</p>
    <div id='div1'>div1</div>
    <p id='p2'>p2</p>
    <div id='div2'>div2</div>
    <button>Submit</button>
</body>
</html>


server.php代码:

<?php
    $id=$_POST['id'];
    if ($id==1){
        sleep(5);
        echo 'one';
    } else {
        sleep(2);
        echo 'two';
    }
?>


效果:发起两个请求之后,请求2的响应反倒比请求1的先完成,和响应1完成与否无关。

62-2.gif

打赏码.png


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