iOS 自定义仿淘宝Tabbar

日常记录工程中（公司产品日常抄淘宝）遇到的问题~~
线上效果图（原谅我没有GIF的图）：

Tabbar效果图1
Tabbar效果图2
解释说明：第一个tabbar点击时“鸡头”顺时针旋转一圈，其余tabbar点击时抖动效果（真的是仿淘宝的）……
→ 好了开始上代码↓：
创建自定义的 SLMainTabbarVc

//SLMainTabbarVC.h 文件
#import <UIKit/UIKit.h>
#import "SLTabBarViewController.h"
@interface SLMainTabbarVC : SLTabBarViewController
@end

//-------------------------------

//SLMainTabbarVC.m 文件
#import "SLMainTabbarVC.h"
#import "ViewController.h"

@implementation SLMainTabbarVC
-(instancetype)init{
    if (self = [super init]) {
        [self createUI];
        self.delegate = self;
    }
    return self;
}

-(void)createUI{
    ViewController *vc1 = [[ViewController alloc] init];
    vc1.hidesBottomBarWhenPushed = NO;
    UINavigationController *nav1 = [[UINavigationController alloc] initWithRootViewController:vc1];
    
    ViewController *vc2 = [[ViewController alloc] init];
    vc2.hidesBottomBarWhenPushed = NO;
    UINavigationController *nav2 = [[UINavigationController alloc] initWithRootViewController:vc2];
    
    ViewController *vc3 = [[ViewController alloc] init];
    vc3.hidesBottomBarWhenPushed = NO;
    UINavigationController *nav3 = [[UINavigationController alloc] initWithRootViewController:vc3];
    
    ViewController *vc4 = [[ViewController alloc] init];
    vc4.hidesBottomBarWhenPushed = NO;
    UINavigationController *nav4 = [[UINavigationController alloc] initWithRootViewController:vc4];
    
    ViewController *vc5 = [[ViewController alloc] init];
    vc5.hidesBottomBarWhenPushed = NO;
    UINavigationController *nav5 = [[UINavigationController alloc] initWithRootViewController:vc5];
    
    NSArray *vc = @[nav1,nav2,nav3,nav4,nav5];
    NSArray *title = @[@"首页",@"分类",@"发现中心",@"购物车",@"个人中心"]; 
    NSArray *image = @[@"tab_1_n-",@"tab_2_n-",@"tab_3_n-",@"tab_4_n-",@"tab_5_n-"];
    NSArray *selectImage = @[@"tab_1_h-",@"tab_2_h-",@"tab_3_h-",@"tab_4_h-",@"tab_5_h-"];
    
    for (int i = 0; i<vc.count; i++) {
        [self addChildViewController:vc[i] andTitle:title[i] image:image[i] selectImage:selectImage[i]];
    }

}

-(void)addChildViewController:(UIViewController *)vc andTitle:(NSString *)title image:(NSString *)image selectImage:(NSString *)selectImage{
    //设置title和图片
    //**特别说明**：见代码后面
    vc.tabBarItem.title = @"";
    vc.tabBarItem.image = [[UIImage imageNamed:image]imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];
    vc.tabBarItem.selectedImage = [[UIImage imageNamed:selectImage] imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];
    
//    //设置文字位置，在有文字时用于调整文字的位置
//    [vc.tabBarItem setTitlePositionAdjustment:UIOffsetMake(0, -2.5)];
    //设置图片位置  注意：图片 上下 or 左右 的间距要一样，否侧有些手机上会变形
    [vc.tabBarItem setImageInsets:UIEdgeInsetsMake(7, 0, -7, 0)]; //
    
    //添加到
     [self addChildViewController:vc];
}

#pragma mark - UITabBarControllerDelegate
//点击下面的tabBar的按钮时候,根据BOOL值来判断是否处于可继续点击状态
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController NS_AVAILABLE_IOS(3_0){
    //此方法里我用来判断在用户点击“个人中心”时是否登录
    return YES;
}

//此方法系统自动调用，写在继承自UITabBarController的controller中
//设置点击的动画----本次重点
-(void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item{
    NSInteger index = [self.tabBar.items indexOfObject:item];
    NSMutableArray * tabbarbuttonArray = [NSMutableArray array];
    for (UIView *tabBarButton in self.tabBar.subviews) {
        if ([tabBarButton isKindOfClass:NSClassFromString(@"UITabBarButton")]) {
            [tabbarbuttonArray addObject:tabBarButton];
        }
    }
    
    if (index == 0) { //顺时针旋转效果
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
        animation.duration = 0.3;
        //如果这里想设置成一直自旋转，可以设置为MAXFLOAT，否则设置具体的数值则代表执行多少次
        animation.repeatCount = 1;
        animation.autoreverses = NO;
        //默认是顺时针效果，若将fromValue和toValue的值互换，则为逆时针效果
        animation.fromValue = [NSNumber numberWithFloat:0.f];
        animation.toValue = [NSNumber numberWithFloat: M_PI *2];
        [[tabbarbuttonArray[index] layer] addAnimation:animation forKey:nil];
        
    }else{ //抖动效果
        CABasicAnimation*pulse = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        pulse.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
        pulse.duration = 0.1;
        pulse.repeatCount = 1;
        pulse.autoreverses = YES;
        pulse.fromValue = [NSNumber numberWithFloat:0.7];
        pulse.toValue = [NSNumber numberWithFloat:1.3];
        [[tabbarbuttonArray[index] layer] addAnimation:pulse forKey:nil];
    }
   
}

//-------------------------------

//在AppDelegate里跟系统的一样使用
    SLMainTabbarVC *tabbar = [[SLMainTabbarVC alloc] init];
    _tabBarVC = tabbar;
    self.window.rootViewController = tabbar;

特别说明：
→1、由于第一个tabbar的“鸡头”不能显示“首页”文字，所以我这里的tabbar没有文字，都是image和title在一起的图片，但是要注意，此时的NavigationController的RootViewController的导航文字不要这样 vc.title = @"首页"；设置，因为这是tabbar的item.title在当前VC显示时对应的tabbar还是会显示 vc.title 的文字。
如果vc的title必须设置，可以用下面方法代替：

-(void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    UILabel *label = [UILabel new];
    label.frame = CGRectMake(0, 0, 100, 40); //防止有些版本手机不显示title的情况，设置一个frame
    label.textAlignment = NSTextAlignmentCenter;
    label.text = @"发现";  
    label.textColor = [UIColor blackColor];
    label.font = [UIFont systemFontOfSize:17];
    self.navigationItem.titleView = label;
}

→2、item.image和item.image分开的情况时的做法跟现在的一样样，在设置addChildViewController方法里 vc.tabBarItem.title = titie; 就可以了。此时的情况本宝宝只试过抖动的效果，别的效果没有试过，同学们可以试着玩玩，指不定就玩出了别的花样_{O(∩_∩)O}~

---

对于tabar的一些延伸
1、tabBarItem的image&title的改变
要求：在用户登录成功后换掉第2个tabBarItem的image，在SLMainTabbarVC.m 文件里接受通知：

//登录成功后通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(theLogin) name:LoginSuccessfullNoticetion object:nil];
//方法
-(void)theLogin{
    UITabBarItem *item = [self.tabBar.items objectAtIndex:1];
    item.image = [[UIImage imageNamed:@"tab_2_d_n-"]imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];
    item.selectedImage = [[UIImage imageNamed:@"tab_2_d_h-"] imageWithRenderingMode:(UIImageRenderingModeAlwaysOriginal)];
}

//代理方法里
-(void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item{
    NSInteger index = [self.tabBar.items indexOfObject:item];
    NSMutableArray * tabbarbuttonArray = [NSMutableArray array];
    for (UIView *tabBarButton in self.tabBar.subviews) {
        if ([tabBarButton isKindOfClass:NSClassFromString(@"UITabBarButton")]) {
            [tabbarbuttonArray addObject:tabBarButton];
        }
    }
    
    //item修改了图片之后，会影响subviews的顺序。
    //修改了第二个的图片，会导致第二个UITabBarButton在subviews变到最后一个，所以根据位置重新排下序
    tabbarbuttonArray = [tabbarbuttonArray sortedArrayUsingComparator:^NSComparisonResult(UIView *obj1, UIView *obj2) {
        NSComparisonResult result = [[NSNumber numberWithFloat:obj1.frame.origin.x] compare:[NSNumber numberWithFloat:obj2.frame.origin.x]];
        return result;
    }];

    //后面内容和上面一样

}