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
