THINKPHP5.1中Request类四种调用方式
1、访问方式$request = new Request();
dump($request->post());exit;
2、静态调用use think\Facade\Request; 
dump(Request::post());exit;
3、依赖注入public function lists(Request $request){
dump($request->post());exit;
4、Controller类中的request属性dump($this->request->post());exit;