//tabBarItem字体大小和颜色
[secondVC.tabBarItemsetTitleTextAttributes:@{NSFontAttributeName:[UIFontsystemFontOfSize:20],NSForegroundColorAttributeName:[UIColorredColor]}forState:UIControlStateNormal];
UINavigationController *secondNC = [[UINavigationControlleralloc]initWithRootViewController:secondVC];
//navigationBar字体大小和颜色
[secondNC.navigationBarsetTitleTextAttributes:@{NSFontAttributeName:[UIFontsystemFontOfSize:20],NSForegroundColorAttributeName:[UIColorredColor]}];
//push下一个界面时,tabBar隐藏,
self.tabBarController.hidesBottomBarWhenPushed=YES;
//UINavigationBar的字体颜色以及返回按钮上出现的上一级title消失
[[UINavigationBar appearance] setTintColor:[UIColor blackColor]];
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)
forBarMetrics:UIBarMetricsDefault];
UINavigationBar *bar = [UINavigationBar appearance];
[bar setBarTintColor:[UIColor whiteColor]];
[UITabBar appearance].tintColor = [UIColor colorWithRed:27/255.0 green:166/255.0 blue:152/255.0 alpha:1];