iOS UITabBarController的使用

    
    UIViewController *vc1 = [[UIViewController alloc] init];
    vc1.view.backgroundColor = [UIColor redColor];
    vc1.title = @"VC1";
    
    // 视图控制器的分栏按钮
    // 视图控制器的分栏按钮，如果没有被显示创建，并且被使用了，则会自动根据视图控制器的title来创建
    //vc1.tabBarItem;
    
    UIViewController *vc2 = [[UIViewController alloc] init];
    vc2.view.backgroundColor = [UIColor yellowColor];
    vc2.title = @"VC2";
    
    UIViewController *vc3 = [[UIViewController alloc] init];
    vc3.view.backgroundColor = [UIColor blueColor];
    vc3.title = @"VC3";
    
    
    UIViewController *vc4 = [[UIViewController alloc] init];
    vc4.view.backgroundColor = [UIColor greenColor];
    vc4.title = @"VC4";
    
    // 创建分栏(标签栏)控制器, 和导航控制器一样，都是用来管理视图控制器的容器类型的控制器。
    // 分栏控制器和导航控制器一样，也是通过viewControllers来管理其子视图控制器
    UITabBarController *tabBarCtrl = [[UITabBarController alloc] init];
    
    tabBarCtrl.view.backgroundColor = [UIColor cyanColor];
    
    // 把数据中得视图器交给分栏控制器管理
    // 分栏控制器会自动将其管理的视图控制器的分栏按钮(UITabBarItem)放到分栏上显示
    tabBarCtrl.viewControllers = @[vc1, vc2, vc3, vc4];
    
    // 设置窗口的跟视图控制器为分栏控制器
    self.window.rootViewController = tabBarCtrl;
    
    // 取到分栏控制器的分栏
    UITabBar *tabBar = tabBarCtrl.tabBar;
    
    // 设置分栏的风格
    tabBar.barStyle = UIBarStyleBlack;
    
    // 是否透明
    tabBar.translucent = NO;
    
    // 设置分栏的前景颜色
    tabBar.barTintColor = [UIColor brownColor];
    
    // 设置分栏元素项的颜色
    tabBar.tintColor = [UIColor purpleColor];
    
    // 设置分栏按钮的选中指定图片
    tabBar.selectionIndicatorImage = [UIImage imageNamed:@"home.png"];
    
    [self.window makeKeyAndVisible];

// 创建分栏控制器管理的子视图控制器
- (void)createViewControllers
{
    OneViewController *oneVC = [[OneViewController alloc] init];
    MyNavgationController *navCtrl1 = [[MyNavgationController alloc] initWithRootViewController:oneVC];
//    navCtrl1.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemSearch tag:0];
    
    TwoViewController *twoVC = [[TwoViewController alloc] init];
    UINavigationController *navCtrl2 = [[UINavigationController alloc] initWithRootViewController:twoVC];
    
    ThreeViewController *threeVC = [[ThreeViewController alloc] init];
    FourViewController *fourVC = [[FourViewController alloc] init];
    
    FiveViewController *fiveVC = [[FiveViewController alloc] init];
    
    SixViewController *sixVC = [[SixViewController alloc] init];
    
    // 分栏控制器管理的视图控制器的tabBarController属性，自动指向分栏控制器。
    // 当分栏控制器管理的视图控制器的个数超过五个时，会自动创建一个more的导航控制器，并且自动将第五个以及以后的视图控制器添加到more导航控制器中。
    self.viewControllers = @[navCtrl1, navCtrl2, threeVC, fourVC, fiveVC,  sixVC];
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    //1. 取出分栏
    UITabBar *tabBar = self.tabBarController.tabBar;
    
    // 将frame左移分栏的宽度
    CGRect frame = tabBar.frame;
    frame.origin.x -= tabBar.frame.size.width;
    
    // 动画影藏tabBar
    [UIView animateWithDuration:0.28 animations:^{
        tabBar.frame = frame;
    }];
    
    [super pushViewController:viewController animated:animated];
}

- (UIViewController *)popViewControllerAnimated:(BOOL)animated
{
    //1. 取出分栏
    UITabBar *tabBar = self.tabBarController.tabBar;
    
    // 将frame左移分栏的宽度
    CGRect frame = tabBar.frame;
    frame.origin.x += tabBar.frame.size.width;
    
    // 动画影藏tabBar
    [UIView animateWithDuration:0.28 animations:^{
        tabBar.frame = frame;
    }];
    
    return [super popViewControllerAnimated:YES];
}

#import "MyTabBar.h"

@interface MyTabBarController () <MyTabBarDelegate>

// 保存之前选中的按钮
@property (nonatomic, retain) UIButton *preSelBtn;
@end

@implementation MyTabBarController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self createViewControllers];
    
    [self createTabBar];
}

// 创建分栏控制器管理的视图控制器数据
- (void)createViewControllers
{
    FirstViewController *firstVC = [[FirstViewController alloc] init];
    UINavigationController *nav1 =[[UINavigationController alloc] initWithRootViewController:firstVC];
    
    SecondViewController *secondVC = [[SecondViewController alloc] init];
    
    ThirdViewController *thirdVC = [[ThirdViewController alloc] init];
    
    FourthViewController *fourthVC = [[FourthViewController alloc] init];
    
    self.viewControllers = @[nav1, secondVC, thirdVC, fourthVC];
}

// 定制tabBar  tabBar 49
- (void)createTabBar
{
    // 0. 隐藏分栏控制器自带的tabbar
    [self.tabBar setHidden:YES];
    
    MyTabBar *tabBr = [[MyTabBar alloc] init];
    
    tabBr.frame = self.tabBar.frame;
    tabBr.delegate = self;
    
    [self.view addSubview:tabBr];
}

#pragma mark - MyTabBarDelegate协议方法
- (void)tabBar:(MyTabBar *)tabBar didSelectItemWithIndex:(NSUInteger)toIndex
{
    // 设置分栏控制器选中的视图控制器
    self.selectedIndex = toIndex;
}

@class MyTabBar;

@protocol MyTabBarDelegate <NSObject>

@optional
- (void)tabBar:(MyTabBar *)tabBar didSelectItemWithIndex:(NSUInteger)toIndex;

- (void)tabBar:(MyTabBar *)tabBar didSelectItemWithIndex:(NSUInteger)toIndex fromIndex:(NSUInteger)fromIndex;

@end


@interface MyTabBar : UIImageView

@property (nonatomic, assign) id <MyTabBarDelegate> delegate;

@end

#import "MyTabBar.h"

#define TABBAR_BTN_START_TAG 100
#define BTN_COUNT  4

@interface TabBarButton : UIButton

@end

@implementation TabBarButton


// 重写高亮的方法。在这个方法中，我们忽略按钮的高亮状态
- (void)setHighlighted:(BOOL)highlighted
{
    //    NSLog(@"highlighted = %d", highlighted);
    //    [super setHighlighted:NO];
}

@end

@interface MyTabBar ()

// 保存分栏之前选中的按钮
@property (nonatomic, retain) TabBarButton *preSelBtn;
@end

@implementation MyTabBar

- (instancetype)init
{
    if (self = [super init]) {
        NSLog(@"init");
    }
    
    return self;
}

// init方法会调用initWithFrame ,给控件添加子控件在initWithFrame中添加
- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        
        // 1.2 设置背景视图的背景图片
        self.image = [UIImage imageNamed:@"tabbg.png"];
        
        // 1.3 设置用户交互属性可用(父控件不能与用户进行交互，则所有子控件都不能与用户交互)
        self.userInteractionEnabled = YES;
        
        // 2. 在分栏背景上添加按钮
        for (int i = 0; i < BTN_COUNT; i++) {
            TabBarButton *btn = [TabBarButton buttonWithType:UIButtonTypeCustom];
            
            // 设置正常状态下的显示图片
            NSString *imageName = [NSString stringWithFormat:@"tab_%d", i];
            [btn setImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];
            
            // 设置按钮在选中状态下的显示图片
            NSString *imageSelName = [NSString stringWithFormat:@"tab_c%d",i];
            [btn setImage:[UIImage imageNamed:imageSelName] forState:UIControlStateSelected];
            
            // 第一个按钮默认为选中
            if (i == 0) {
                btn.selected = YES;
                self.preSelBtn = btn;
            }
            
            // 监听按钮的点击事件
            [btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchDown];
            
            btn.tag = TABBAR_BTN_START_TAG + i;
            
            // 将按钮添加到背景视图上显示
            [self addSubview:btn];
        }
    }
    
    return self;
}


- (void)btnClick:(TabBarButton *)btn
{
    // 1. 取消之前选中按钮的选中状态
    self.preSelBtn.selected = NO;
    
    // 2. 将当前点击的按钮设为选中状态
    btn.selected = YES;
    
    // 3. 保存当前选中的按钮
    self.preSelBtn = btn;
    
    // 如果代理实现了协议方法，通过协议方法通知代码当前控件上的第几个按钮被点击了。
    if ([self.delegate respondsToSelector:@selector(tabBar:didSelectItemWithIndex:)]) {
        
        [self.delegate tabBar:self didSelectItemWithIndex:btn.tag - TABBAR_BTN_START_TAG];
    }
}


// 这个方法在控件的frame(大小)修改后被调用
- (void)layoutSubviews
{
    // 这行代码不能少
    [super layoutSubviews];
    
    // 取出子控件的个数
    NSUInteger count = self.subviews.count;
    
    // 调整子控件的大小
    CGFloat btnY = 0;
    CGFloat btnW = self.bounds.size.width / count;
    CGFloat btnH = self.bounds.size.height;
    
    int i = 0;
    // 取出所有的子控件,调整frame
    for (TabBarButton *btn in self.subviews) {
        // 设置frame
        CGFloat btnX = btnW * i;
        btn.frame = CGRectMake(btnX, btnY, btnW, btnH);
        i++;
    }
}