CYLTabBarController，一个用于快速集成TabBarController的第三方。

在appdelegate中

@interface AppDelegate ()<UITabBarControllerDelegate,CYLTabBarControllerDelegate>
@property (nonatomic, strong) UITabBarController *tabBarController;
@end

@implementation AppDelegate


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [SmallOneBtn registerPlusButton]; //添加额外按钮的时候调用
    [self setupViewControllers];
    [self.window setRootViewController:self.tabBarController];
    [self customizeInterface];
    return YES;
}

- (void)setupViewControllers {
    OneViewController *firstViewController = [[OneViewController alloc] init];
    UIViewController *firstNavigationController = [[UINavigationController alloc]
                                                   initWithRootViewController:firstViewController];
    
    TwoViewController *secondViewController = [[TwoViewController alloc] init];
    UIViewController *secondNavigationController = [[UINavigationController alloc]
                                                    initWithRootViewController:secondViewController];
    ThreeViewController *threeVC = [[ThreeViewController alloc] init];
    UIViewController *threeNavi = [[UINavigationController alloc]
                                                   initWithRootViewController:threeVC];
    FourViewController *fourVC = [[FourViewController alloc] init];
    UIViewController *fourNavi = [[UINavigationController alloc]
                                   initWithRootViewController:fourVC];
    
    
    CYLTabBarController *tabBarController = [[CYLTabBarController alloc] init];
    [self customizeTabBarForController:tabBarController];
    
    [tabBarController setViewControllers:@[
                                           firstNavigationController,
                                           secondNavigationController,threeNavi,fourNavi
                                           ]];
    self.tabBarController = tabBarController;
    self.tabBarController.delegate = self;
    
}

- (void)customizeTabBarForController:(CYLTabBarController *)tabBarController {
    
    NSDictionary *dict1 = @{
                            CYLTabBarItemTitle : @"首页",
                            CYLTabBarItemImage : @"item1",
                            CYLTabBarItemSelectedImage : @"item1_press",
                            };
    NSDictionary *dict2 = @{
                            CYLTabBarItemTitle : @"发现",
                            CYLTabBarItemImage : @"发现",
                            CYLTabBarItemSelectedImage : @"发现_press",
                            };
    NSDictionary *dict3 = @{
                            CYLTabBarItemTitle : @"个人中心",
                            CYLTabBarItemImage : @"item3",
                            CYLTabBarItemSelectedImage : @"item3_press",
                            };
    NSDictionary *dict4 = @{
                            CYLTabBarItemTitle : @"设置",
                            CYLTabBarItemImage : @"item3",
                            CYLTabBarItemSelectedImage : @"item3_press",
                            };
    
    NSArray *tabBarItemsAttributes = @[ dict1, dict2, dict3, dict4];
    tabBarController.tabBarItemsAttributes = tabBarItemsAttributes;
}

/**
 *  tabBarItem 的选中和不选中文字属性、背景图片
 */
- (void)customizeInterface {
    
    // 普通状态下的文字属性
    NSMutableDictionary *normalAttrs = [NSMutableDictionary dictionary];
    normalAttrs[NSForegroundColorAttributeName] = [UIColor grayColor];
    
    // 选中状态下的文字属性
    NSMutableDictionary *selectedAttrs = [NSMutableDictionary dictionary];
    selectedAttrs[NSForegroundColorAttributeName] = [UIColor redColor];
    
    // 设置文字属性
    UITabBarItem *tabBar = [UITabBarItem appearance];
    [tabBar setTitleTextAttributes:normalAttrs forState:UIControlStateNormal];
    [tabBar setTitleTextAttributes:selectedAttrs forState:UIControlStateSelected];
    
    // 设置背景图片
    UITabBar *tabBarAppearance = [UITabBar appearance];
    [tabBarAppearance setBackgroundImage:[UIImage imageNamed:@""]];
}

- (void)tabBarController:(UITabBarController *)tabBarController didSelectControl:(UIControl *)control {
    UIView *animationView;
    // 如果 PlusButton 也添加了点击事件，那么点击 PlusButton 后不会触发该代理方法。
    if ([control isKindOfClass:[CYLExternPlusButton class]]) {
        UIButton *button = CYLExternPlusButton;
        animationView = button.imageView;
    } else if ([control isKindOfClass:NSClassFromString(@"UITabBarButton")]) {
        for (UIView *subView in control.subviews) {
            if ([subView isKindOfClass:NSClassFromString(@"UITabBarSwappableImageView")]) {
                animationView = subView;
            }
        }
    }
    
    if ([self cyl_tabBarController].selectedIndex % 2 == 0) {
        [self addScaleAnimationOnView:animationView];
    } else {
        [self addRotateAnimationOnView:animationView];
    }
}

//缩放动画
- (void)addScaleAnimationOnView:(UIView *)animationView {
    //需要实现的帧动画，这里根据需求自定义
    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];
    animation.keyPath = @"transform.scale";
    animation.values = @[@1.0,@1.3,@0.9,@1.15,@0.95,@1.02,@1.0];
    animation.duration = 1;
    animation.calculationMode = kCAAnimationCubic;
    [animationView.layer addAnimation:animation forKey:nil];
}

//旋转动画
- (void)addRotateAnimationOnView:(UIView *)animationView {
    [UIView animateWithDuration:0.32 delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{
        animationView.layer.transform = CATransform3DMakeRotation(M_PI, 0, 1, 0);
    } completion:nil];
    
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        [UIView animateWithDuration:0.70 delay:0 usingSpringWithDamping:1 initialSpringVelocity:0.2 options:UIViewAnimationOptionCurveEaseOut animations:^{
            animationView.layer.transform = CATransform3DMakeRotation(2 * M_PI, 0, 1, 0);
        } completion:nil];
    });
}

需要集成非常规额外的按钮时候，需要继承CYLPlusButton类，并遵循代理CYLPlusButtonSubclassing。

#import "SmallOneBtn.h"
#import "CYLTabBarController.h"
#import "ThreeViewController.h"

@interface SmallOneBtn ()<UIActionSheetDelegate> {
    CGFloat _buttonImageHeight;
}

@end
@implementation SmallOneBtn

+ (void)load {
    //请在 `-application:didFinishLaunchingWithOptions:` 中进行注册，否则iOS10系统下存在Crash风险。
    //[super registerPlusButton];
}

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.titleLabel.textAlignment = NSTextAlignmentCenter;
        self.adjustsImageWhenHighlighted = NO;
    }
    return self;
}

//上下结构的 button
- (void)layoutSubviews {
    [super layoutSubviews];
    
    // 控件大小,间距大小
    // 注意：一定要根据项目中的图片去调整下面的0.7和0.9，Demo之所以这么设置，因为demo中的 plusButton 的 icon 不是正方形。
    CGFloat const imageViewEdgeWidth   = self.bounds.size.width * 0.7;
    CGFloat const imageViewEdgeHeight  = imageViewEdgeWidth * 0.9;
    
    CGFloat const centerOfView    = self.bounds.size.width * 0.5;
    CGFloat const labelLineHeight = self.titleLabel.font.lineHeight;
    CGFloat const verticalMargin  = (self.bounds.size.height - labelLineHeight - imageViewEdgeHeight) * 0.5;
    
    // imageView 和 titleLabel 中心的 Y 值
    CGFloat const centerOfImageView  = verticalMargin + imageViewEdgeHeight * 0.5;
    CGFloat const centerOfTitleLabel = imageViewEdgeHeight  + verticalMargin * 2 + labelLineHeight * 0.5 + 5;
    
    //imageView position 位置
    self.imageView.bounds = CGRectMake(0, 0, imageViewEdgeWidth, imageViewEdgeHeight);
    self.imageView.center = CGPointMake(centerOfView, centerOfImageView);
    
    //title position 位置
    self.titleLabel.bounds = CGRectMake(0, 0, self.bounds.size.width, labelLineHeight);
    self.titleLabel.center = CGPointMake(centerOfView, centerOfTitleLabel);
}

#pragma mark -
#pragma mark - CYLPlusButtonSubclassing Methods

/*
 *
 Create a custom UIButton with title and add it to the center of our tab bar
 *
 */
+ (id)plusButton {
    SmallOneBtn *button = [[SmallOneBtn alloc] init];
    UIImage *buttonImage = [UIImage imageNamed:@"post_normal"];
    [button setImage:buttonImage forState:UIControlStateNormal];
    [button setTitle:@"发布" forState:UIControlStateNormal];
    [button setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
    
    [button setTitle:@"发布" forState:UIControlStateSelected];
    [button setTitleColor:[UIColor blueColor] forState:UIControlStateSelected];
    
    button.titleLabel.font = [UIFont systemFontOfSize:9.5];
    [button sizeToFit]; // or set frame in this way `button.frame = CGRectMake(0.0, 0.0, 250, 100);`
    //    button.frame = CGRectMake(0.0, 0.0, 250, 100);
    //    button.backgroundColor = [UIColor redColor];
    
    // if you use `+plusChildViewController` , do not addTarget to plusButton.
    [button addTarget:button action:@selector(clickPublish) forControlEvents:UIControlEventTouchUpInside];
    return button;
}
/*
 *
 Create a custom UIButton without title and add it to the center of our tab bar
 *
 */
//+ (id)plusButton
//{
//
//    UIImage *buttonImage = [UIImage imageNamed:@"hood.png"];
//    UIImage *highlightImage = [UIImage imageNamed:@"hood-selected.png"];
//
//    CYLPlusButtonSubclass* button = [CYLPlusButtonSubclass buttonWithType:UIButtonTypeCustom];
//
//    button.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleTopMargin;
//    button.frame = CGRectMake(0.0, 0.0, buttonImage.size.width, buttonImage.size.height);
//    [button setBackgroundImage:buttonImage forState:UIControlStateNormal];
//    [button setBackgroundImage:highlightImage forState:UIControlStateHighlighted];
//    [button addTarget:button action:@selector(clickPublish) forControlEvents:UIControlEventTouchUpInside];
//
//    return button;
//}

#pragma mark -
#pragma mark - Event Response

- (void)clickPublish {
    CYLTabBarController *tabBarController = [self cyl_tabBarController];
    UIViewController *viewController = tabBarController.selectedViewController;
    
    UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:nil
                                                             delegate:nil
                                                    cancelButtonTitle:@"取消"
                                               destructiveButtonTitle:nil
                                                    otherButtonTitles:@"拍照", @"从相册选取", @"淘宝一键转卖", nil];
    [actionSheet showInView:viewController.view];
}

#pragma mark - UIActionSheetDelegate

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex {
    NSLog(@"buttonIndex = %@", @(buttonIndex));
}

#pragma mark - CYLPlusButtonSubclassing


//+ (UIViewController *)plusChildViewController {
//    UIViewController *plusChildViewController = [[UIViewController alloc] init];
//    plusChildViewController.view.backgroundColor = [UIColor greenColor];
//    plusChildViewController.navigationItem.title = @"PlusChildViewController";
//    UIViewController *plusChildNavigationController = [[UINavigationController alloc]
//                                                   initWithRootViewController:plusChildViewController];
//    return plusChildNavigationController;
//}
//中间按钮的位置
+ (NSUInteger)indexOfPlusButtonInTabBar {
    return 2;
}
//
//+ (BOOL)shouldSelectPlusChildViewController {
//    BOOL isSelected = CYLExternPlusButton.selected;
//    if (isSelected) {
//        NSLog(@"🔴类名与方法名：%@（在第%@行），描述：%@", @(__PRETTY_FUNCTION__), @(__LINE__), @"PlusButton is selected");
//    } else {
//        NSLog(@"🔴类名与方法名：%@（在第%@行），描述：%@", @(__PRETTY_FUNCTION__), @(__LINE__), @"PlusButton is not selected");
//    }
//    return YES;
//}

//constantOfPlusButtonCenterYOffset 为0，同时 multiplierOfTabBarHeight 的值是0.5，表示 PlusButton 居中，小于0.5表示 PlusButton 偏上，大于0.5则表示偏下。
+ (CGFloat)multiplierOfTabBarHeight:(CGFloat)tabBarHeight {
    return  0.3;
}

+ (CGFloat)constantOfPlusButtonCenterYOffsetForTabBarHeight:(CGFloat)tabBarHeight {
    return  -0;
}

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