iOS开篇——UI之UITabBarController

UITabBarController的创建与基本属性

- (void)customTabbarController{
    
    //声明一个UITabBarController
    UITabBarController * tab = [[UITabBarController alloc]init];
    
    //设置tabBar是否透明
    tab.tabBar.translucent = YES;
    //设置tabBarController的代理
    tab.delegate = self;
    //设置背景图片
//    tab.tabBar.backgroundImage = [UIImage imageNamed:@""];
    
//    tab.tabBar.alpha =1;
//    tab.tabBar.backgroundColor =
//    设置样式
//    tab.tabBar.barStyle = UIBarStyleDefault;
    /*
     typedef NS_ENUM(NSInteger, UIBarStyle) {
     UIBarStyleDefault          = 0,
     UIBarStyleBlack            = 1,
     
     UIBarStyleBlackOpaque      = 1, // Deprecated. Use UIBarStyleBlack
     UIBarStyleBlackTranslucent = 2, // Deprecated. Use UIBarStyleBlack and set the translucent property to YES
     } __TVOS_PROHIBITED;
     */
    
    //设置为根视图
    _window.rootViewController = tab;
    
    //先声明试图控制器对象
    FirstViewController * firstVC = [[FirstViewController alloc]init];
        //用系统创建tabBar样式
//    firstVC.tabBarItem = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemFeatured tag:1];
    
    //使用标题 图片创建tabBar样式
    firstVC.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"首页" image:[UIImage imageNamed:@"tabbar_account"] tag:1];
//    [tab addChildViewController:firstVC];

    //设置提示 可以是中文 可以是数字 字符串
    firstVC.tabBarItem.badgeValue = @"1";
    //将firstVC设置为nav1的根视图
    UINavigationController * nav1 = [[UINavigationController alloc]initWithRootViewController:firstVC];

    
    
    SecondViewController * secondVC = [[SecondViewController alloc]init];
//    secondVC.tabBarItem = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemBookmarks tag:2];
    secondVC.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"钱" image:[[UIImage imageNamed:@"tabbar_appfree"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] tag:2];
//    [tab addChildViewController:secondVC];
    secondVC.tabBarItem.badgeValue = @"2";
    UINavigationController * nav2 = [[UINavigationController alloc]initWithRootViewController:secondVC];
    
    
    ThirdViewController * thirdVC = [[ThirdViewController alloc]init];
//    thirdVC.tabBarItem = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemContacts tag:3];
    thirdVC.tabBarItem = [[UITabBarItem alloc]initWithTitle:@"图表" image:[UIImage imageNamed:@"tabbar_rank@2x"] selectedImage:[UIImage imageNamed:@"tabbar_rank_press@2x"]];
//    [tab addChildViewController:thirdVC];
    UINavigationController * nav3 = [[UINavigationController alloc]initWithRootViewController:thirdVC];
    
    
    FourthViewController * fourthVC = [[FourthViewController alloc]init];
    fourthVC.tabBarItem = [[UITabBarItem alloc]initWithTabBarSystemItem:UITabBarSystemItemHistory tag:4];
//    [tab addChildViewController:fourthVC];
    fourthVC.tabBarItem.badgeValue = @"3";
//    fourthVC.title = @"hhehe";
//    fourthVC.navigationItem.prompt = @"ooo";
    UINavigationController * nav4 = [[UINavigationController alloc]initWithRootViewController:fourthVC];
    
    
    
    //声明一个单例
    NSUserDefaults * ud = [NSUserDefaults standardUserDefaults];
    //找到key为selected的值
    NSUInteger index = [[ud objectForKey:@"selected"] integerValue];
    //设置tabBarController的索引值 （默认页面）
    tab.selectedIndex = index;
    
    
    //按数组顺序显示  初始是第一个
    //把试图控制器添加上去 此处添加的是navigationController
    tab.viewControllers = @[nav1,nav2,nav3,nav4];
    
//    [tab addChildViewController:firstVC];
//



    //系统样式
    /*
     typedef NS_ENUM(NSInteger, UITabBarSystemItem) {
     UITabBarSystemItemMore,
     UITabBarSystemItemFavorites,
     UITabBarSystemItemFeatured,
     UITabBarSystemItemTopRated,
     UITabBarSystemItemRecents,
     UITabBarSystemItemContacts,
     UITabBarSystemItemHistory,
     UITabBarSystemItemBookmarks,
     UITabBarSystemItemSearch,
     UITabBarSystemItemDownloads,
     UITabBarSystemItemMostRecent,
     UITabBarSystemItemMostViewed,
     };
     */
}

再看看 协议UITabBarControllerDelegate中的代理方法

//能否选择viewController
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController{
    //第二个参数为点击的视图控制器
    
    //获取到tabBarController所有的视图控制器
    NSArray * array = tabBarController.viewControllers;
    
    NSUInteger index = [array indexOfObject:viewController];
    NSLog(@"%lu",index);
    
    //声明一个单例
    NSUserDefaults * ud = [NSUserDefaults standardUserDefaults];
    [ud setObject:[NSNumber numberWithInteger:index] forKey:@"selected"];
    //写入磁盘
    [ud synchronize];

    return YES;
}
//点击之后
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
    
}