//1.设置
self.tabBarController.tabBar.hidden=YES;
//2.如果在push跳转时需要隐藏tabBar,设置
self.hidesBottomBarWhenPushed=YES;
NewViewController *new=[[NewViewController alloc]init];
[self.navigationController pushViewController:new animated:YES];
//并在push后设置
self.hidesBottomBarWhenPushed=NO;
//back回来,tabBar会恢复正常显示。