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.
}