$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
            }