<?php
if($_FILES){
?>
<script>
window.parent.ajaxUploadPicture.uploadCallback('http://img0.bdstatic.com/img/image/5099213b07eca8065380ce7f75e95dda144ad348269.jpg');
</script>
<?php
die;
}
?>
<!DOCTYPE html>
<html>
<head>
<script>
ajaxUploadPicture = { $o1:'' };
ajaxUploadPicture.ajaxUploadFile = function ($o){
this.$o1 = $o;
var $iframe = document.createElement('iframe');
$iframe.style.display = 'none';
$iframe.name = 'iframe';
$iframe.id = 'iframe';
document.body.appendChild($iframe);
var $form = document.createElement("form");
$form.method = "post";
$form.enctype = "multipart/form-data";
$form.action = "";
$form.target = 'iframe';
$newO = $o.cloneNode();
$form.appendChild($newO);
$form.submit();
}
ajaxUploadPicture.uploadCallback = function ($url){
$pic = document.createElement('img');
$pic.width = "200";
$pic.height = "150";
$pic.src = $url;
if(document.getElementById('picshow') == null){
$div = document.createElement("div");
$div.id = 'picshow';
this.$o1.parentNode.insertBefore($div,this.$o1.nextSibling);
}else{
$div = document.getElementById('picshow');
}
$div.innerHTML = '';
$div.appendChild($pic);
};
</script>
</head>
<body>
<input type="file" name="file" onchange = "ajaxUploadPicture.ajaxUploadFile(this);">
</body>
</html>
面向对象思想，form提交到一个隐藏的iframe，执行回调js函数。实现图片回显。后台php的功能没有完善。