ajax--iframe simulates ajax file upload effect

js does not have the right to read local files, so cannot upload files, but
there are several methods
1 iframe disguises jquery-uploaded-file
2 swf plug-in (not to mention this, it is a separate software
3 html5

iframe simulates ajax file upload effect
1 Capture form submission action
2 Create iframe
3 Target modification points to iframe
4 Remove iframe

<h1></h1>
<!-- enctype 属性可能的值：
application/x-www-form-urlencoded
multipart/form-data
text/plain
规定在发送表单数据之前如何对其进行编码。

target
规定在何处打开 action URL。（这边是iframe里） 
onsubmit 点击运行js的方法通过才到｀action

文件上传说没上传  enctype没写-->
	

js part (using jquery) Create iframe

<script type="text/javascript" src="http://libs.baidu.com/jquery/1.7.2/jquery.min.js"></script>
	
	<script type="text/javascript">
	function upfile(){
		// 创建iframe 和属性name
		var ifname = &#39;up&#39;+Math.random();
		$(&#39;<iframe name="&#39; + ifname +&#39;">&#39;).appendTo($(&#39;body&#39;));
		// form表单加入target属性，form点击在iframe打开
		$(&#39;form:first&#39;).attr(&#39;target&#39;,ifname);

	}


	</script>

php part If the error is 0 On behalf of the successful file upload, a message will appear in the h1 tag written before.

<?php if(empty($_FILES)){
	exit(&#39;no file&#39;);
}

$error = $_FILES[&#39;pic&#39;][&#39;error&#39;] == 0 ? &#39;上传成功&#39;:&#39;上传失败&#39;;
echo "<script> parent.document.getElementsByTagName('h1')[0].innerHTML = '$error'";

?>

The above introduces the effect of ajax--iframe simulating ajax file upload, including the content. I hope it will be helpful to friends who are interested in PHP tutorials.