由来:在上传文件过程中，如果文件过大第一占用服务器带宽，所以为了减少网络代码，提高用户体验度在客户端【浏览器】首先将资源【图片，资源】使用分页原理将资源切分，然后上传至服务器，最后服务器进行合并，形成图片
1.前端代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script src="./jquery.js"></script>
</head>
<body>
<div id="per_box" style="width: 350px; height: 15px; background-color: #cccccc">
<div id="per" style="width: 0%; height: 100%; background-color: #007CD5"></div>
<span id="per_num"></span>
</div>
<br />
<input type="file" name="file_tag" id="file_tag">
<input type="button" value="上传" id = "upload_btn">
</body>
</html>
<script>
$(document).ready(function(){
$("#upload_btn").click(function(){
var files = $("#file_tag")[0].files[0];
if(!files){
$("#file_tag").trigger("click");
}
var chunk;//当前页面数值
upload(files);
});
function upload(file){
var tmpName = file.size+"_chunk";
var every_size=1024*1024;//每一页传递的数据
var chunks = Math.ceil(file.size /every_size);//一共多少页
chunk = window.localStorage.getItem(tmpName) || 1;
chunk = parseInt(chunk);
var offset = (chunk-1) * every_size;//开始位置
var limit = chunk * every_size > file.size ? file.size : chunk * every_size;
var page = file.slice(offset,limit);//获取一页的数据
var form = new FormData();//这是一个表单的对象
form.append("page",page);//类似于一个input框
form.append("filename",file.name);//文件名字
var per = (limit/file.size * 100).toFixed(1);
$.ajax({
type : "post",
data:form,
processData : false,//取消服务器对上传文件线程控制
contentType : false,//取消服务器设置上传文件的类型
cache : false,//不需要服务器设置缓存
dataType : 'json',
url : "/upload.php",
success:function(msg){
if(chunk >= chunks ){
$("#per").css({width:"100%"});
$("#per_num").text(100+"%");
}else{
chunk++;
window.localStorage.setItem(tmpName,chunk);
$("#per").css({width:per+"%"});
$("#per_num").text(per+"%");
upload(file);
}
}
});
}
});
</script>
2.后端代码
$baseFileName = $_REQUEST['filename'];
$ext = explode(".",$baseFileName)[1];
$fileName=explode(".",$baseFileName)[0];
$arr = $_FILES['page'];
$tmpName = $arr['tmp_name'];
$content = file_get_contents($tmpName);
$fileName = "./{$fileName}.{$ext}";
file_put_contents($fileName,$content,FILE_APPEND);
$arr = array(
'error'=>0,
);
echo json_encode($arr);
标签：chunk,per,切片,tmpName,file,var,php,上传,size From： https://blog.51cto.com/u_11635800/5877041