這些內(nèi)容通常寫(xiě)在+initialize方法里

//首先拿到UITabBar
UITabBar * tab = [UITabBar appearance];
//背景顏色
//tab.barTintColor = [UIColor yellowColor];
//前景顏色
//tab.tintColor = [UIColor orangeColor];
//設(shè)置背景圖片
[tab setBackgroundImage:[UIImage imageNamed:@"tabbar"]];
//設(shè)置透明度
tab.alpha = 0.3;
// UIControlStateNormal狀態(tài)下的文字屬性
 NSMutableDictionary * dictionary = [NSMutableDictionary dictionary];
//文字顏色
dictionary[NSForegroundColorAttributeName] = [UIColor blackColor];
//文字大小
dictionary[NSFontAttributeName] = [UIFont systemFontOfSize:12];

// UIControlStateSelected狀態(tài)下的文字屬性
NSMutableDictionary * seleDictionary = [NSMutableDictionary dictionary];
seleDictionary[NSForegroundColorAttributeName] = [UIColor colorWithRed:255 / 256.0 green:255 / 256.0  blue:130 / 256.0 alpha:1];

UITabBarItem * itme = [UITabBarItem appearance];
[itme setTitleTextAttributes:dictionary forState:UIControlStateNormal];
[itme setTitleTextAttributes:seleDictionary forState:UIControlStateSelected];
//每一個(gè)控制器都有tabBarItem這個(gè)屬性
childController.tabBarItem.image = [UIImage imageNamed:image];
childController.tabBarItem.selectedImage = [UIImage imageNamed:selectImage];
childController.tabBarItem.badgeValue = @"11";
//設(shè)置消息標(biāo)題的字體大小
[item setBadgeTextAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:25]} forState:UIControlStateNormal];