UITabBarItem 只显示图片的实现
UITabBarItem *tabBarItem = [[UITabBarItem alloc] initWithTitle:@"" image:[UIImage imageNamed:@"tab_home"] selectedImage:[UIImage imageNamed:@"tab_home"]];
tabBarItem.imageInsets = UIEdgeInsetsMake(9, 0, -9, 0);
UITabBarItem *tabBarItem = [[UITabBarItem alloc] initWithTitle:@"" image:[UIImage imageNamed:@"tab_home"] selectedImage:[UIImage imageNamed:@"tab_home"]];
tabBarItem.imageInsets = UIEdgeInsetsMake(9, 0, -9, 0);