设置 NavigationBarItem背景颜色 & t

// 设置 NavigationBar 背景颜色 & title 颜色
[self.navigationController.navigationBar setBarTintColor:[UIColor colorWithRed:20/255.0 green:20/255.0 blue:20/255.0 alpha:1.0]];
[self.navigationController.navigationBar setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[UIColor whiteColor], NSForegroundColorAttributeName, nil]];