Sae平台的上传图片写法

用thinkphp3.2.3的liaray中的Think文件下面的upload.class.php的实现，网上百度搜出来的真的是五花八门，各种各样，自己实践总结出来上传图片基于thinkphp3.2.3正确写法

if (!empty($_FILES)) {

                if($_FILES['img']['size']>2*1024*1024){ 

                    $this->error("上传图片大小不能大于2M");

                }

                $config=array(

                    'exts'=>array('jpg','gif','png'),

                    'rootPath'=>'./public/', //sae上的domain

                    'savePath'=>'upload/', //sae会自动创建

                    'saveRule'=>'time',

                );

                $upload = new \Think\Upload($config,'Sae');  //sae一定要写

                $upload->thumb=false;

                if (!$info=$upload->upload()) {

                    echo $upload->getError();die;

                    $this->error($upload->getError());

                } else {

                    $_POST['img']=$info['img']['url'];

                }

                if(M("work")->add($_POST)){ 

                    $this->success("提交成功",U('Index/work'));

                }else{ 

                    $this->error("提交失败");

                }

            }