获取导航栏，状态栏，tabBar高度

状态栏

CGFloat statusHeight = [[UIApplication sharedApplication] statusBarFrame].size.height;

导航栏

CGFloat navigationHeight = self.navigationController.navigationBar.frame.size.height;

tabBar

//在tabBarController中使用（你的继承自UITabBarController的VC）
CGFloat tabBarHeight = self.tabBar.frame.size.height;
//在非tabBarController中使用
UITabBarController *tabBarVC = [[UITabBarController alloc] init];(这儿取你当前tabBarVC的实例)
CGFloat tabBarHeight = tabBarVC.tabBar.frame.size.height;

toolBar

CGFloat toolBarHeight = self.navigationController.toolBar.frame.size.height;