UITabBarController学习案例之一

包括UITabBarController的基本使用:

1.建立7个 UIVIEWController实例;

2.对标签使用了图片;

3.对MORE里面的EDIT使用了代理;

 

主要步骤:

1.建立一个IOS EMPTY PROJECT;

2.command+n,新建7个继承自uiviewcontroller的实例文件;

3.在appdelegate.m里面import这7个头文件;

4.在didFinishLaunchingWithOptions函数里面,填入如下代码:

    RedViewController   *red = [[RedViewController alloc]init];
    GreenViewController *green = [[GreenViewController  alloc]init];
    BlueViewController  *blue = [[BlueViewController alloc] init];
    BlackViewController *black = [[BlackViewController alloc] init];
    YellowViewController *yellow = [[YellowViewController alloc] init];
    PurpleViewController *purple = [[PurpleViewController alloc] init];
    OrangeViewController *orange = [[OrangeViewController alloc] init];
    

    red.title   = @"微信";
    green.title = @"通讯录";
    blue.title  = @"发现";
    black.title = @"我";
    yellow.title = @"1";
    purple.title = @"2";
    orange.title = @"3";
    
    //对前两个使用NAV CONTROLLER
    UINavigationController *redNav = [[UINavigationController alloc] initWithRootViewController:red];
    UINavigationController *greenNav = [[UINavigationController alloc] initWithRootViewController:green];
    
    //使用自定义图标
    if (0)
    {
        red.tabBarItem.image = [UIImage imageNamed:@"tab_0.png"];
        green.tabBarItem.image = [UIImage imageNamed:@"tab_1.png"];
        blue.tabBarItem.image = [UIImage imageNamed:@"tab_2.png"];
        black.tabBarItem.image = [UIImage imageNamed:@"tab_3.png"];
    }
    //使用系统自定义图标
    else
    {
        /*
         UITabBarSystemItemMore,
         UITabBarSystemItemFavorites,
         UITabBarSystemItemFeatured,
         UITabBarSystemItemTopRated,
         UITabBarSystemItemRecents,
         UITabBarSystemItemContacts,
         UITabBarSystemItemHistory,
         UITabBarSystemItemBookmarks,
         UITabBarSystemItemSearch,
         UITabBarSystemItemDownloads,
         UITabBarSystemItemMostRecent,
         UITabBarSystemItemMostViewed,
         */

　　　　 //设定每个标签的徽标,模拟 "当前有多少信息未读" 场景
        red.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFavorites tag:1];
        red.tabBarItem.badgeValue = @"2";
        green.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemBookmarks tag:2];
        green.tabBarItem.badgeValue = @"4";
        blue.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemSearch tag:3];
        blue.tabBarItem.badgeValue = @"100";
        black.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemDownloads tag:4];
        black.tabBarItem.badgeValue = @"14";
    }
    
    //字面值进行NSARRAY创建,默认是AUTORELEASE模式,不需要显式 release
    NSArray *vcArray = @[redNav, greenNav, blueNav, blackNav, yellow, purple, orange];
    
    //使用MVC内存管理
    [redNav release];
    [blueNav release];
    [greenNav release];
    [blackNav release];
    [red release];
    [green release];
    [blue release];
    [black release];
    [yellow release];
    [purple release];
    [orange release];
    
    //创建标签控制器
    UITabBarController  *tabController = [[UITabBarController alloc] init];
    tabController.viewControllers = vcArray; //加入标签列表
    tabController.delegate = self;  //设置代理为本APP
    tabController.selectedIndex = 0; //默认初始时被选择的标签
    
    //输出一个标签栏的尺寸
    NSLog(@"height %f", tabController.tabBar.frame.size.height);
    
    self.window.rootViewController = tabController;
    
    [tabController release];

　　接着,因为标签多于5个,会显式MORE标签,里面会有EDIT按钮,以下代码是实现UITabBarControllerDelegate代理协议的:

- (void) tabBarController:(UITabBarController *)tabBarController willBeginCustomizingViewControllers:(NSArray *)viewControllers
{
    NSLog(@"当点击MORE-EDIT时调用,将要开始时调用");
    [viewControllers enumerateObjectsUsingBlock:^(UIViewController *obj, NSUInteger idx, BOOL *stop){
        NSLog(@"VC title = %@", obj.title);
    }];
}

- (void)tabBarController:(UITabBarController *)tabBarController willEndCustomizingViewControllers:(NSArray *)viewControllers changed:(BOOL)changed
{
    NSLog(@"即将结束编辑");
    if (changed) //如果为真,就表示标签位置发生了变化
    {
        UIViewController *obj;
        
        obj = (UIViewController *)[viewControllers objectAtIndex:3];
        
　　　　 //如果第四个标签被换成了第五个标签,给一个提示
        if([obj.title isEqualToString:@"1"])
        {
            UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"View Changed" message:@"Tab view has changed" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles: nil] autorelease];
            [alert show];
　　　　　　　[alert release];
　　　　 }
    }
}

- (void)tabBarController:(UITabBarController *)tabBarController didEndCustomizingViewControllers:(NSArray *)viewControllers changed:(BOOL)changed
{
    NSLog(@"结束编辑");
    [viewControllers enumerateObjectsUsingBlock:^(UIViewController *obj, NSUInteger idx, BOOL *stop){
        NSLog(@"VC title = %@", obj.title);
    }];
    
}