TP中上传文件图片的实现

GoodsController.class.php控制器页面
<?php
      namespace Admin\Controller;
      use Think\Controller;
      class GoodsController extends Controller{
           public function  tianjia(){
             $goods=D('Goods');
             if(!empty($_POST)){
                 if($_FILES['f_goods_image']['error']<4){
                    $cfg=array( 
                   'rootPath' =>  './Public/uploadss/', 
                               );//保存根路径
                     $up=new \Think\Upload($cfg);
                     $z= $up->uploadOne($_FILES['f_goods_image']);
                    //  dump($up->getError());
                    //dump($z);
                    //把上传好的附件上传到数据库里面
                    $_POST['goods_big_img']=  $up->rootPath .$z['savepath'].$z['savename'];
                 }
                 //收集表单
                 $shuju=$goods->create();
                 $z=$goods->add($shuju);
                 if($z){
                     $this->redirect('showlist',3, '添加商品成功'); 
                 }  else {
                     $this->redirect('tianjia',3,'添加商品失败');    
                 }
             }  else {
                 //展示表单
                     $this->display(); 
             }
         }
}