IOS学习实例之五---三级控制器

本实例主要涉及自定义标签栏，三种不同的控制器协调实现导航。

重点：三级控制器，自定义标签

三级控制器： 标签控制器（主控制器），导航控制器，视图控制器

UITabBarController, UINavigationController, UIViewController

源码：

https://github.com/ianzhengnan/TabBar

极客学院视频：

http://www.jikexueyuan.com/course/431.html

实例使用描述：

点击底部标签栏可以实现不同视图的跳转，点击导航栏上的按钮可以跳入新的视图，点击dismiss按钮返回。

点击首页的push按钮跳入新的视图，点击pop返回。

两种导航方式：

1. 模态方式： 这种方式是从视图控制器出发，返回方式是dismiss

2. push方式： 这种方式是从导航控制器出发，返回方式是pop

效果图：

点击push

点击pop返回

重点：

实现步骤：

1. 新建项目，导入素材图片，添加类RootViewController 继承自UITabBarController

2. 在AppDelegate.m中的didFinishLaunchingWithOptions添加如下代码，设置主视图

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.        self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];    self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];        RootViewController *rootVC = [[RootViewController alloc] init];        //权限最高的给根视图控制器: 标签控制器－－－控制－－－导航控制器－－－控制－－－视图控制器    self.window.rootViewController = rootVC;        return YES;}

3. 分别创建五个视图控制器用来对应底部标签栏的五个按钮

4. 在RootViewController中初始化这几个视图控制器，并把它们的实例放入数组。

//initial view controller- (void)initViewController{        ProfileViewController *profileVC = [[ProfileViewController alloc] init];    MessageViewController *messageVC = [[MessageViewController alloc] init];    ColaViewController *colaVC = [[ColaViewController alloc] init];    UserViewController *userVC = [[UserViewController alloc] init];    MoreViewController *moreVC = [[MoreViewController alloc] init];    //store view controllers    NSArray *vcArray = @[profileVC, messageVC, colaVC, userVC, moreVC];    //store navigation controllers    NSMutableArray *tabArray = [[NSMutableArray alloc] initWithCapacity:vcArray.count];        for (int i=0; i < vcArray.count; i++) {        UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:vcArray[i]];        [tabArray addObject:navCtrl];    }    //assign navigation controllers to tabbar controller    self.viewControllers = tabArray;}

5. 自定义标签栏：确定标签栏的位置，背景颜色以及分别创建上面的按钮。并把它添加到主视图中。

//customize tab bar- (void)initTabBarView{    //initial tab bar view    _tabBarView = [[UIView alloc] initWithFrame:CGRectMake(0, kScreenHeight - tabViewHeight, kScreenWidth, tabViewHeight)];    _tabBarView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"mask_navbar"]];    [self.view addSubview:_tabBarView];        //add a array and get the images    NSArray *imageArray = @[@"home_tab_icon_1",@"home_tab_icon_2",@"home_tab_icon_3",@"home_tab_icon_4",@"home_tab_icon_5"];        //create buttons    for (int i = 0; i < imageArray.count; i++) {        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];                [btn setBackgroundImage:[UIImage imageNamed:imageArray[i]] forState:UIControlStateNormal];                btn.frame = CGRectMake(btnWidth * i, (tabViewHeight - btnHeight)/2, btnWidth, btnHeight);                //set tag for button, and make sure tag is great than 100 since the number less than 100 has been reserved by system        btn.tag = 100 + i;        //add click event for button        [btn addTarget:self action:@selector(btnAction:) forControlEvents:UIControlEventTouchUpInside];                [self.tabBarView addSubview:btn];    }    //initial selected imageview    _selectView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, btnWidth, btnHeight)];    _selectView.image = [UIImage imageNamed:@"home_bottom_tab_arrow"];    [_tabBarView addSubview:_selectView];}

6. 设置标签栏每个按钮的点击事件相应方法

#pragma mark - UIButtonAction- (void)btnAction:(UIButton *)button{    //get current index by tag value    self.selectedIndex = button.tag - 100;        //add a animation for selected image    [UIView animateWithDuration:0.2 animations:^{        _selectView.center = button.center;    } completion:nil];    }

7. 在首页视图中实现模态方式跳转

1）自定义导航栏按钮

注意：这里添加按钮的方式有变化，不是addSubview了。

而必须使用UIBarButtonItem的方式

//customize navigation bar button- (void)initNavButton{    UIButton *writeBtn = [UIButton buttonWithType:UIButtonTypeCustom];        writeBtn.frame = CGRectMake(0, 0, writeButtonWidth, writeButtonHeight);    [writeBtn setBackgroundImage:[UIImage imageNamed:@"write"] forState:UIControlStateNormal];    [writeBtn addTarget:self action:@selector(presentAction) forControlEvents:UIControlEventTouchUpInside];    //add the btn to navigation bar    UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithCustomView:writeBtn];    self.navigationItem.leftBarButtonItem = item;}

2）实现模态方式跳转

- (void)presentAction{    ModelViewController *modelVC = [[ModelViewController alloc] init];    //模态视图的方式， 从视图控制器出发，返回方式是dismiss    [self presentViewController:modelVC animated:YES completion:nil];}

3）使用dismiss方式实现返回。

- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    self.view.backgroundColor = [UIColor blueColor];        UIButton *pushButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];    pushButton.frame = CGRectMake(100, 200, 200, 40);    [pushButton setTitle:@"Dismiss" forState:UIControlStateNormal];    [pushButton addTarget:self action:@selector(dismissAction) forControlEvents:UIControlEventTouchUpInside];        [self.view addSubview:pushButton];}- (void)dismissAction{    [self dismissViewControllerAnimated:YES completion:nil];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}

8. 实现push方式跳转

1）自定义push按钮

//customize push button- (void)initPushButton{        UIButton *pushButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];        pushButton.frame = CGRectMake(100, 200, 200, 40);    //[pushButton setImage:<#(UIImage *)#> forState:<#(UIControlState)#>]    //title and image cannot appear together    [pushButton setTitle:@"Push" forState:UIControlStateNormal];    [pushButton addTarget:self action:@selector(pushAction) forControlEvents:UIControlEventTouchUpInside];        [self.view addSubview:pushButton];    }

2）push方式跳转

- (void)pushAction{    //push方式，从导航控制器出发，返回方式是pop    PushViewController *pushVC = [[PushViewController alloc] init];    [self.navigationController pushViewController:pushVC animated:YES];    RootViewController *rootVC = (RootViewController *)self.tabBarController;        [rootVC showTabBar:NO];        // the new method to show view controller    //[self.navigationController showViewController:<#(UIViewController *)#> sender:<#(id)#>]}

3）pop方式返回

- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    self.view.backgroundColor = [UIColor greenColor];        UIButton *pushButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];    pushButton.frame = CGRectMake(100, 200, 200, 40);    [pushButton setTitle:@"Pop" forState:UIControlStateNormal];    [pushButton addTarget:self action:@selector(popAction) forControlEvents:UIControlEventTouchUpInside];        [self.view addSubview:pushButton];}- (void)popAction{    [self.navigationController popViewControllerAnimated:YES];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}