PHP+Ajax异步带进度条上传文件实例

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css">
<script src="http://apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://malsup.github.com/jquery.form.js"></script>

<script type="text/javascript">
$(function () {
   $("#myupload").ajaxform({
     datatype:'json',
     beforesend:function(){ 
         $(".progress").show();
     },
     uploadprogress:function(event,position,total,percentcomplete){
         var percentval = percentcomplete + '%';
         $(".progress-bar").width(percentcomplete + '%');
         $(".progress-bar").html(percentval);
         $(".sr-only").html(percentcomplete + '%');
     },
     success:function(data){
         $(".progress").hide();
      
         if(data.error == "empty_name"){
             alert("文件上传非法,上传失败!");
             exit();
         };
         if(data.error == "large"){
             alert("图片上传不能大于2m,上传失败!");
             exit();
         };
  
 /*alert(data.error);*/
         if(data.error == "format"){
             alert("图片格式错误,上传失败");
             //alert(data.type);
             exit();
         };
  
         //alert("上传成功!");
         //files.html("<b>"+data.name+"("+data.size+"k)</b> <span class='delimg' rel='"+data.pic+"'>删除</span>");
         $(".files").html("文件名: "+data.name+"<span class='delimg' rel='"+data.pic+"'>  del  </span>大小："+data.size);
         var img = "http://www.sandleft.com/test/input/upload/files/"+data.pic;
         $(".showimg").html("<img src='"+img+"'>");
         alert("上传成功!");
     },
     error:function(){
         alert("图片上传失败");
     }
      
   });
   $(".progress").hide();
});
 
</script>

<div class="uk-container uk-container-center">
 
        <div class="pk-system-messages"></div>
 
        <h1 class="uk-h2 uk-text-center" style="margin-top:-100px;">文件上传</h1>
        <div class="pk-system-messages"></div>
 
         <div class="container-main">
          <h1>ajax image uploader</h1>
          <p>a simple tutorial to explain image uploading using jquery ajax and php</p>
  
           <form id='myupload' action='new_upload.php' method='post' enctype='multipart/form-data'>
            <label for="file">filename:</label>
           <input type="file" name="mypic" id="file"><br>
           <input type="submit" name="upload" class="btn btn-success" value="upload">
          </form>
  
            <div class="progress">
             <div class="progress-bar progress-bar-success progress-bar-striped" role="progressbar" aria-valuenow="45" aria-valuemin="0" aria-valuemax="100" style="width: 0%">
              <span class="sr-only">0% complete</span>
           </div>
           </div>
          <div class="files"></div>
          <div class="showimg"></div>
         </div>
         
       </div>

<?php
class upload{
 
  protected $file_path = "files"; //当前files存储文件夹
  #protected $file_size = 1024000;
  protected $file_size = 5120000; //5m 用户上传
  //检测文件是否为空
 public function check_file($get_file)
 {
    if (empty($get_file))
    {
     $type = "check_file";
       $arr = array('error'=>'empty_name','type'=>$type);
       echo json_encode($arr);
       exit();
    }
  return true;
}
 
 
 //检测文件类型
 public function check_type($get_type)
 {
   if (( $get_type == ".docx" ) || ( $get_type == ".doc" )) {
      #$types = $get_type;
   }else{
      $type = "check_type";
      $arr = array('error'=>'format','type'=>$type);
        echo json_encode($arr);
        exit(); 
 
   }
  return true;
 }
 
 //检测文件大小
 public function check_size($get_file)
 {
   if ( $get_file != "" ) {
      if ( $get_file > $this->file_size ) {
          $arr = array('error'=>'large');
          echo json_encode($arr);
          exit();
      }
  }else{
    return false;
    exit();
  }
 return true;
 }
  
//文件保存
 public function save_file($file_type,$file_tmp_name)
 {
  $rand = rand(1000, 9999);
  $pics = date("ymdhis") . $rand . $file_type;
  $path = $this->file_path."/".$pics;
  $result = move_uploaded_file($file_tmp_name, $path);
  if($result){
    return $pics;
  }else{
    return false;
    exit();
  }
  #return $pics;
 }
 
}
php文件上传处理
<?php
include("upload.class.php");
$up_obj = new upload();
 
$get_filename = $_files['mypic']['name'];
$get_filesize = $_files['mypic']['size'];
$get_tmpfiles = $_files['mypic']['tmp_name'];
 
$get_filetype = strstr($get_filename, '.');
 
$check_result = $up_obj->check_file($get_filename);
 
if($check_result){
 
  //检查文件类型
  $result_type = $up_obj->check_type($get_filetype);
 
  //检查文件大小
  if($result_type){
 
    $result_size = $up_obj->check_size($get_filesize);
 
    if($result_size){
      //文件上传保存  
      $pics = $up_obj->save_file($get_filetype,$get_tmpfiles);   
      $size = round($get_filesize/1024,2);
          $arr = array(
            'name' => $get_filename,
             'pic' => $pics,
             'size'=> $size,
             'error' => 2
         );
 
       //检查文件上传状态
       if($pics){
         echo json_encode($arr);
         /*
         执行上传完成逻辑.....
         */
      }   
    }
  }
 
}