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")); }