Question

我有一个表有一个事务列表，我试图按设定的时间间隔更新表内容。我在linux red hat服务器上运行此页面。这只是AJAX现在无法正常工作。

<!doctype html>
<html>

    <head>
        <script>
            function updateTrans() {
                var xmlhttp;

                if (window.XMLHttpRequest) {
                    xmlhttp = new XMLHttpRequest();
                } else {
                    xmlhttp = new ActiveXObject("Microsoft.HTTP");
                }

                xmlhttp.onreadystatechange = function () {

                    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                        document.getElementById("transactions").innerHTML = xmlhttp.responseText;
                    }

                }

                xmlhttp.open("GET", "update_trans.txt", true);
                xmlhttp.send();
            }

            window.setInterval(updateTrans(), 4000);
        </script>
        <link href="trans_styles.css" rel="stylesheet" type="text/css">
    </head>

    <body>
         <h1 id="heading"> Chomp The Bit </h1>

        <div id="transactions">
            <table id="trans_tbl" border="0">
                <tr>
                    <th colspan="2">Latest Transactions</th>
                </tr>
                <tr>
                    <td>aaaaaaaaaaaaaaaaaaaaaaaaaaaaa</td>
                    <td>aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</td>
                </tr>
                <tr>
                    <td>bbbbbbbbbbbbbbbbbbbbbbbbbbbbb</td>
                    <td>bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb</td>
                </tr>
                <tr>
                    <td>ccccccccccccccccccccccccccccc</td>
                    <td>cccccccccccccccccccccccccccccc</td>
                </tr>
                <tr>
                    <td>ddddddddddddddddddddddddddddd</td>
                    <td>dddddddddddddddddddddddddddddd</td>
                </tr>
                <tr>
                    <td>eeeeeeeeeeeeeeeeeeeeeeeeeeeee</td>
                    <td>eeeeeeeeeeeeeeeeeeeeeeeeeeeeeee</td>
                </tr>
                <tr>
                    <td>fffffffffffffffffffffffffffff</td>
                    <td>ffffffffffffffffffffffffffffffff</td>
                </tr>
                <tr>
                    <td>ggggggggggggggggggggggggggggg</td>
                    <td>gggggggggggggggggggggggggggggggg</td>
                </tr>
                <tr>
                    <td>hhhhhhhhhhhhhhhhhhhhhhhhhhhhh</td>
                    <td>hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh</td>
                </tr>
                <tr>
                    <td>iiiiiiiiiiiiiiiiiiiiiiiiiiiiii</td>
                    <td>iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii</td>
                </tr>
                <tr>
                    <td>jjjjjjjjjjjjjjjjjjjjjjjjjjjjjj</td>
                    <td>jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj</td>
                </tr>
            </table>
        </div>
    </body>

</html>

Answer 1

确保在同一目录中包含update_trans.txt文件，并且该文件不为空。

        <head>
            <script>
                function updateTrans() {
                    var xmlhttp;

                    if (window.XMLHttpRequest) {
                        xmlhttp = new XMLHttpRequest();
                    } else {
                        xmlhttp = new ActiveXObject("Microsoft.HTTP");
                    }

                    xmlhttp.onreadystatechange = function () {

                        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                            document.getElementById("transactions").innerHTML = xmlhttp.responseText;
                        }

                    }

                    xmlhttp.open("GET", "update_trans.txt", true);
                    xmlhttp.send();
                }

                window.setInterval(updateTrans(), 4000);
            </script>
            <link href="trans_styles.css" rel="stylesheet" type="text/css">
        </head>

        <body>
             <h1 id="heading"> Chomp The Bit </h1>

            <div id="transactions">

             </div>
        </body>

    </html>

Answer 2

我不确定这是否可以解决问题，但您应该window.setInterval(updateTrans, 4000)而不是window.setInterval(updateTrans(), 4000)。也就是说，你应该将对函数的引用作为setInterval的第一个参数传递，而不是调用函数的返回值，这是你在当前代码中所做的。在您当前的代码中，updateTrans将被调用一次 - 当您自己调用它时 - 但不会像您想要的那样每4000ms调用一次。

我还建议您使用setTimeout代替setInterval - 我写了a post about this。

无法让AJAX脚本工作

2 个答案: