HTML调用“ajax_request('server_code.php','result_id')”onClick。它第一次失败时出现此错误:
*未捕获TypeError:无法读取null的属性'innerHTML'ajax_request ajax.js:35(匿名函数)*
但每次后续通话都能完美运行。为什么..?
在此处下载所有文件:http://k.min.us/iejWmy.zip
HTML:
<html>
<head>
<!-- ajax -->
<script src='ajax.js' type='text/javascript'></script>
</head>
<body>
<a id='test' href='#' onclick="ajax_request('php.php','show_result')">get ajax data</a>
<div id='show_result'></div>
<body>
</html>
Javascript'ajax.js'
/****************************************************************************
Iframes based AJAX function.
@ url - server side script location
@ result_id - server side script output
****************************************************************************/
function ajax_request(url,result_id)
{
var ajax_iframe_id = 'ajax_iframe_loader';
var ajax_iframe = document.getElementById(ajax_iframe_id);
// create hidden iframe transfer buffer if it's not created already.
if (ajax_iframe == null)
{
var element = document.createElement("iframe");
element.setAttribute('src',url);
element.setAttribute('id',ajax_iframe_id);
document.body.appendChild(element);
element.style.display='none';
element.style.width='1';
element.style.height='1';
element.style.border='0';
ajax_iframe = element;
}
// load server side page into iframe buffer
ajax_iframe.src = url;
// get the outputted result from inside our transfer div
var iframe_inner_doc = ajax_iframe.contentDocument || ajax_iframe.contentWindow.document;
// target AJAX data to transfer
var content_to_transfer = iframe_inner_doc.getElementById('to_transfer').innerHTML;
// paste result
document.getElementById(result_id).innerHTML = content_to_transfer;
}
PHP'php.php'
<html>
<body>
<div id='to_transfer'>random number via ajax is:<font size='15'><?=mt_rand(5, 15);?></font></div>
</body>
</html>
答案 0 :(得分:0)
我看到你设置了iframe src,但没有设置AJAX。我怀疑你在iframe之前试图访问iframe的内容。一旦你加载了内容,就会存在to_transfer,但这不是第一次,因为你没有给它机会加载内部文档内容。