$config=array(

                'maxSize'   => 3145728,

                'savePath'  => './Public/Uploads/',

                'rootPath'  => './',          //这样写上传到网站根目录下的public下

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

                'autoSub'   => true,

                'subName'   => array('data','Ymd')

            );    //定义配置数组

            $upload = new \Think\Upload($config);   //实例化上传对象

            $info = $upload -> uploadOne($_FILES['peitu']);    // 执行单个图片上传，并获取上传结果

            if(!$info){

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

            }else{

                $data['img_src'] = $info['savepath'].$info['savename'];        //将上传文件的保存路径存到数据库以便前台调用

            }