push时隐藏tabBar的正确使用

self.hidesBottomBarWhenPushed = YES;

有时候push过去时会正常隐藏tabBar，但是push back后tabBar又不显示了，此时可以重写navigationController的pushViewController方法

“`

-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{

viewController.hidesBottomBarWhenPushed = YES;

[super pushViewController:viewController animated:animated];
 viewController.hidesBottomBarWhenPushed = NO;
           

}

“`