异步上传文件以及php对文件的处理

来源：互联网发布：360智能摄像机软件编辑：程序博客网时间：2024/05/16 05:10

通过隐藏的iframe来实现异步上传

html代码:
<form name='edit_form' action="" method="POST" enctype="multipart/form-data" target='upload_file'>
<input name="userfile" id="userfile" type="file" />

    <input type="hidden" name="MAX_FILE_SIZE" value="2097152">
<input type='submit' value='提交'>  <input type='reset' name='reset'>
</form>
<iframe src="" name="upload_file" width="0" height="0" style="display:none;"></iframe>

=========================================================================================================
php代码:
            $uploaddir = "upload/img/";
           $ext = substr(strrchr($_FILES['userfile']['name'], '.'), 1);
           $uploadfile = $uploaddir.time().rand(0,999).".".$ext;
           if($_FILES['userfile']['type'] == 'image/jpeg' || $_FILES['userfile']['type'] == 'image/gif')
           {

           }
           else
           {
               echo "<script>alert('错误的文件类型！');</script>";
               exit;
           }

           switch ($_FILES["userfile"]["error"])
           {
               case 0:
                   if (file_exists($uploadfile))
                   {
                       echo "<script>alert('".$_FILES["userfile"]["name"]."已存在"."');</script>";
                       break;
                   }
                   else
                   {

                       if(move_uploaded_file($_FILES["userfile"]["tmp_name"],$uploadfile))
                       {
                            echo "success";
                       }
                       else
                       {
                           echo "<script>alert('上传图片失败！');</script>";
                           break;
                       }
                   }
               case 1:
                   echo "<script>alert('大小超过upload_max_filesize限制!');</script>";
                   break;
               case 2:
                   echo "<script>alert('大小超过MAX_FILE_SIZE限制！');</script>";
                   break;
               case 3:
                   echo "<script>alert('文件只有部分被上传！');</script>";
                   break;
               case 6:
                   echo "<script>alert('找不到临时文件夹！');</script>";
                   break;
               case 7:
                   echo "<script>alert('文件写入失败！');</script>";
                   break;
           }