在PHP5.4以前, 我们可以通过APC提供的功能来实现. 或者使用PECL扩展uploadprogress来实现.
虽然说, 它们能很好的解决现在的问题, 但是也有很明显的不足:
- 1. 他们都需要额外安装(我们并没有打算把APC加入PHP5.4)
- 2. 它们都使用本地机制来存储这些信息, APC使用共享内存, 而uploadprogress使用文件系统(不考虑NFS), 这在多台前端机的时候会造成麻烦.
程序需要php的apc模块的支持,关键点就是在上传的form里添加一个hidden的inpu标签,里面要有name为
APC_UPLOAD_PROGRESS的属性,value值为一个随机数一遍多个人上传。
apc模块的安装方法是,下载php_apc.dll放到ext文件夹下,在php.ini文件里添加
upload_max_filesize =100M
apc.rfc1867 = on
apc.max_file_size = 100M
extension=php_apc.dll
然后测试配置是否成功:
if(apc_fetch)
{echo "apc is working"}
else{echo "apc is not supported!";}
运行效果截图
下面是源码
1 前台页面:
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<html>
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<title>PHP+Ajax带进度条文件上传</title>
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<head>
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<style type="text/css">
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#progress{
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border:2px red solid;
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width:200px;
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height:20px;
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display:none;
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}
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#pecent{
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background-color:green;
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display:block;
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width:0px;
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height:20px;
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color:yellow;
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}
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</style>
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</head>
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<body>
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<iframe style="display:none" name="ifm"></iframe>
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<form enctype="multipart/form-data" method="POST" action="upload.php" target="ifm" name="myform">
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<input type="hidden" name="APC_UPLOAD_PROGRESS" id="remark" >
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<input type="file" name="upfile"/>
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<input type="submit" value="上传" name="sub"/>
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</form>
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<div id="progress" class="before"><span id="pecent"></span></div>
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<script type="text/javascript">
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(function(){
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function addEvent( node, type, listener ) {
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if (node.addEventListener) {
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// W3C method
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node.addEventListener( type, listener, false );
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return true;
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} else if(node.attachEvent) {
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// MSIE method
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node['e'+type+listener] = listener;
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node[type+listener] = function(){node['e'+type+listener]( window.event );}
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node.attachEvent( 'on'+type, node[type+listener] );
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return true;
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}
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// Didn't have either so return false
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return false;
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};
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var submit=document.forms["myform"];
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addEvent(submit,'submit',startUpload);
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var begin;
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var request;
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var rdm;
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var pec=document.getElementById("pecent");
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function startUpload()
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{
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rdm=Math.floor(Math.random()*100000000);
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document.getElementById('remark').setAttribute('value',rdm);
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document.getElementById("progress").style['display']='block';
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//creatXmlHttpRequest();
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begin=setTimeout(doRequest,1000);
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};
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function creatXmlHttpRequest()
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{
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if(window.ActiveXObject)
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{request=new ActiveXObject("Microsoft.XMLHTTP")}
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else{request=new XMLHttpRequest();}
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};
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var count=0;
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function doRequest()
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{
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if(window.ActiveXObject)
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{request=new ActiveXObject("Microsoft.XMLHTTP");}
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else{request=new XMLHttpRequest();}
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if(request!=null){
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request.onreadystatechange=handle;
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request.open("GET","upload.php?key="+rdm+"&sim=" + (++count),true);
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request.send();
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}
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};
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function handle()
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{
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if(request.readyState==4&&request.status==200)
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{
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//接受服务器数据
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var prgs=eval("(" + request.responseText + ")");
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//var prgs=request.responseText;
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var cur=parseInt(prgs.current);
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var total=parseInt(prgs.total);
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var pecentIs=Math.round(cur/total*100);
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pec.innerHTML=pecentIs.toString()+"%";
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if(100==pecentIs)
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{
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pec.style['width']="200px";
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clearTimeout(begin);
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}else{
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begin=setTimeout(doRequest,1000);
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//alert(pecentIs);
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pec.style['width']=pecentIs*2;
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}
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}
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};
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})();
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</script>
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</body>
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</html>
2后台upload.php文件代码:
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<?php
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if ($_SERVER['REQUEST_METHOD'] == 'POST'){
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$myfile=$_FILES['upfile'];
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echo $myfile['size'];
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echo $myfile['size'];
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print_r($myfile);
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$tempf=$myfile['tmp_name'];
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$name=$myfile['name'];
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move_uploaded_file($tempf,'up/'.$name);}
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if(isset($_GET['key']))
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{
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echo json_encode(getStatusAPC());
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}
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function getStatusAPC()
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{
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$response=false;
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if($status = apc_fetch('upload_'.$_GET['key'])) {
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$response=apc_fetch('upload_'.$_GET['key']);
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}
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return $response;
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}
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?>
问题总结:
1,使用setTimeout嵌套和setInterval有区别,用前者效果较好,用后者的话由于请求和返回的时间比较随机,时间间隔把握不好的话,程序会比较混乱,结果往往不正确。
2.发送Ajax请求时每次都要重新实例化xmlhttprequest对象而不能用上次实例化的,否则程序在ie下无法执行,在火狐下可以运行
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