ajax上传图片到PHP并压缩图片显示的方法

<div id="main"> 
 <div class="demo"> 
  <div class="btn btn-success"> 
   <span>上传图片</span> 
   <input id="fileupload" type="file" name="mypic"> 
  </div> 
  <!--加载进度--> 
  <div class="progress progress-striped"> 
   <span class="progress-bar progress-bar-success bar" role="progressbar" aria-valuenow="60" aria-valuemin="0" aria-valuemax="100" style=""></span> 
   <span class="percent">0%</span > 
  </div> 
  <!--显示图片--> 
  <div id="showimg"></div> 
  <!--删除图片--> 
  <div class="files"></div> 
 </div> 
</div> 

<style type="text/css"> 
 .demo{width:580px; margin:30px auto} 
 .btn{position: relative;overflow: hidden;margin-right: 4px;} 
 .btn input {position: absolute;top: 0; right: 0;margin: 0;border: solid transparent;opacity: 0;filter:alpha(opacity=0);} 
 .progress { position:relative; margin-left:100px; margin-top:-24px; width:200px; border-radius:3px; display:none} 
 .percent { position:absolute; top:1px; left:2%; color:#fff } 
 .files{margin:10px 0} 
 .delimg{margin-left:20px; color:#090; cursor:pointer;margin-top: -6px;} 
</style> 
<!--bootstrap.css3.3.7--> 
<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va PmSTsz/K68vbdEjh4u" crossorigin="anonymous"> 

<!--jquery1.8.1--> 
 <script src="http://code.jquery.com/jquery-1.8.1.min.js"></script> 
 <!--图片jquery.form.js--> 
 <script type="text/javascript" src="https://www.helloweba.net/demo/upload/jquery.form.js"></script> 
<script type="text/javascript"> 
 $(function () { 
  //进度条百分比加载颜色 
  var bar = $('.bar'); 
  //进度条百分比 
  var percent = $('.percent'); 
  //图片显示 
  var showimg = $('#showimg'); 
  //进度条 
  var progress = $(".progress"); 
  //新增 
  var files = $(".files"); 
  var btn = $(".btn span"); 
  $(".demo").wrap("<form id='myupload' action='action.php' method='post' enctype='multipart/form-data'></form>"); 
  //点击上传图片 
  $("#fileupload").change(function(){ 
   //提交表单 
   $("#myupload").ajaxSubmit({ 
    dataType: 'json', 
    beforeSend: function() { 
 
     //显示进度条 
     progress.show(); 
     //进度条为0 
     var percentVal = '0%'; 
     bar.width(percentVal); 
     percent.html(percentVal); 
     btn.html("上传中..."); 
    }, 
    //上传进度 
    uploadProgress: function(event, position, total, percentComplete) { 
     //进度条加载长度数据是number型 
     var percentVal = percentComplete   '%'; 
     bar.width(percentVal) 
     percent.html(percentVal); 
    }, 
    success: function(data) { 
     //上传成功返回参数 
     files.html("<b>" data.name "(" data.size "k)</b> <span class='delimg btn btn-danger' rel='" data.pic "'>删除</span>"); 
     showimg.html("<img src='" data.pic "'>"); 
     btn.html("上传图片"); 
    }, 
    error:function(xhr){ 
     //上传失败 
     btn.html("上传失败"); 
     bar.width('0') 
     files.html(xhr.responseText); 
    }, 
    clearForm: true 
   }); 
  }); 
 
  //删除图片js 
  $(".delimg").live('click',function(){ 
   //获取图片地址 
   var pic = $(this).attr("rel"); 
   $.post("action.php?act=delimg",{imagename:pic},function(msg){ 
    if(msg=='delete'){ 
     files.html("删除成功."); 
     //删除图片效果 
     showimg.empty(); 
     //隐藏进度条 
     progress.hide(); 
    }else{ 
     alert(msg); 
    } 
   }); 
  }); 
 }); 
</script> 

<?php 
date_default_timezone_set("PRC"); 
//引入图片压缩类 
require 'imgcompress.class.php'; 
//如果有数据就是当前数据，没有为空 
$action=isset($_GET['act']) ? $action = $_GET['act']:''; 
$filename=isset($_POST['imagename']) ? $_POST['imagename']:''; 
 
if($action=='delimg'){ 
 
 if(!empty($filename)){ 
  //删除图片 
  unlink($filename); 
  //向页面回调参数 
  echo 'delete'; 
 }else{ 
  echo '删除失败.'; 
 } 
 }else{ 
 //获取图片名字和原数据 
 $picname = $_FILES['mypic']['name']; 
 //获取图片大小 
 $picsize = $_FILES['mypic']['size']; 
 
 
 if ($picname != "") { 
 
  /** 
   * 
   * 注释代码为是否限制用户上传图片大小和用户上传文件格式 
   */ 
//  if ($picsize > 512000) { //限制上传大小 
//   echo '图片大小不能超过500k'; 
//   exit; 
//  } 
//  $type = strstr($picname, '.'); //限制上传格式 
//   if ($type != ".gif" && $type != ".jpg") { 
//       echo '图片格式不对！'; 
//    exit; 
//   } 
//  $rand = rand(100, 999); 
//  $pics = date("YmdHis") . $rand . $type; //命名图片名称 
 
  //防止上传图片名中文乱码 
  $name=iconv("UTF-8","gb2312", $picname); 
  //上传路径 
  $pic_path = "files/". $name; 
  //移动图片位置 
  move_uploaded_file($_FILES['mypic']['tmp_name'], $pic_path); 
 } 
 //图片地址 拿到图片地址可以传递到数据库 
 $source = "files/". $picname; 
 $size = round($picsize/1024,2); //转换成kb 
 $arr = array( 
  'name'=>$picname, 
  'pic'=>$source, 
  'size'=>$size 
 ); 
 echo json_encode($arr); //输出json数据 
 
 
 $dst_img = $picname; 
 $percent = 1; //原图压缩，不缩放 
 /** 
  * 方法一 
  * 压缩图片传递三个参数 
  * 1.资源文件 
  * 2.压缩图片质量 1是最高，从0.1开始 
  * 3.图片压缩名字 
  */ 
 (new Compress($source,$percent))->compressImg($dst_img); 
 
 /** 
  * 方法二 
  * 1.资源文件 
  * 2.压缩图片质量 
  * 3.图片名字 
  */ 
// require 'image.class.php'; 
// $src = "001.jpg"; 
// $image = new Image($src);·············· 
// $image->percent = 0.2; 
// $image->saveImage(md5("aa123")); 
}