iOS TabBarController的几种动画效果的实现

正常情况下，我们点击tabbar都只有一个变色效果，但有时候，如果我们想给它添加一个点击动画，该如何做呢？
先上几个效果图：
1、先放大，再缩小

511196-20170116103844396-1872210226.gif

2、Z轴旋转

511196-20170116103932614-876709799.gif

3、放大并保持

511196-20170116104036224-920525159.gif

4、 y轴位移

511196-20170116104000302-95725194.gif

原理：利用UITabBarController实现，在tabbar的 didSelectItem 代理里添加动画效果。

下面就以上几种场景贴上代码：

准备代码：

@interface MainTabbarVC ()<UITabBarControllerDelegate>
@property (nonatomic,assign) NSInteger  indexFlag;　　//记录上一次点击tabbar，使用时，记得先在init或viewDidLoad里 初始化 = 0
@end


-(void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item{
    NSInteger index = [self.tabBar.items indexOfObject:item];
    if (index != self.indexFlag) {
        //执行动画
        NSMutableArray *arry = [NSMutableArray array];
        for (UIView *btn in self.tabBar.subviews) {
            if ([btn isKindOfClass:NSClassFromString(@"UITabBarButton")]) {
                 [arry addObject:btn];
            }
        }
        //添加动画
　　　　 //---将下面的代码块直接拷贝到此即可---

        self.indexFlag = index;
    }
}

1、先放大，再缩小

//放大效果，并回到原位
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
//速度控制函数，控制动画运行的节奏
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
animation.duration = 0.2;       //执行时间
animation.repeatCount = 1;      //执行次数
animation.autoreverses = YES;    //完成动画后会回到执行动画之前的状态
animation.fromValue = [NSNumber numberWithFloat:0.7];   //初始伸缩倍数
animation.toValue = [NSNumber numberWithFloat:1.3];     //结束伸缩倍数
[[arry[index] layer] addAnimation:animation forKey:nil];

2、Z轴旋转

//z轴旋转180度
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
//速度控制函数，控制动画运行的节奏
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
animation.duration = 0.2;       //执行时间
animation.repeatCount = 1;      //执行次数
animation.removedOnCompletion = YES;
animation.fromValue = [NSNumber numberWithFloat:0];   //初始伸缩倍数
animation.toValue = [NSNumber numberWithFloat:M_PI];     //结束伸缩倍数
[[arry[index] layer] addAnimation:animation forKey:nil];

3、Y轴位移

//向上移动
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.translation.y"];
//速度控制函数，控制动画运行的节奏
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
animation.duration = 0.2;       //执行时间
animation.repeatCount = 1;      //执行次数
animation.removedOnCompletion = YES;
animation.fromValue = [NSNumber numberWithFloat:0];   //初始伸缩倍数
animation.toValue = [NSNumber numberWithFloat:-10];     //结束伸缩倍数
[[arry[index] layer] addAnimation:animation forKey:nil];

4、放大并保持

//放大效果
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
//速度控制函数，控制动画运行的节奏
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
animation.duration = 0.2;       //执行时间
animation.repeatCount = 1;      //执行次数
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;           //保证动画效果延续
animation.fromValue = [NSNumber numberWithFloat:1.0];   //初始伸缩倍数
animation.toValue = [NSNumber numberWithFloat:1.15];     //结束伸缩倍数
[[arry[index] layer] addAnimation:animation forKey:nil];
//移除其他tabbar的动画
for (int i = 0; i<arry.count; i++) {
    if (i != index) {
        [[arry[i] layer] removeAllAnimations];
    }
}

此外，如果想定制其他动画效果，还可以从下面属性里自己定制动画

511196-20170116093610724-1578979553.png

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