iOS开发中仿Tumblr点赞心破碎动画效果

<span style="font-size:14px;">- (void)setupUI {   // 点击的btn   UIButton *praiseBtn = [UIButton buttonWithType:UIButtonTypeCustom];   praiseBtn.frame = CGRectMake(100, 200, KKPraiseBtnWH, KKPraiseBtnWH);   [praiseBtn setImage:[UIImage imageNamed:@"icon_like"] forState:UIControlStateNormal];   [praiseBtn setImage:[UIImage imageNamed:@"icon_likeon"] forState:UIControlStateSelected];   [self.view addSubview:praiseBtn];   [praiseBtn addTarget:self action:@selector(clickTheBtn:) forControlEvents:UIControlEventTouchUpInside];   _praiseBtn = praiseBtn;   // 放大后的btn   _coverBtn = [UIButton buttonWithType:UIButtonTypeCustom];   _coverBtn.frame = praiseBtn.frame;   _coverBtn.alpha = 0;   [_coverBtn setImage:[UIImage imageNamed:@"big"] forState:UIControlStateSelected];   [_coverBtn setImage:[UIImage imageNamed:@"big"] forState:UIControlStateNormal];   [self.view insertSubview:_coverBtn belowSubview:praiseBtn];   _cancelPraiseImg = [[UIImageView alloc]initWithFrame:CGRectMake(80, 150, KKPraiseBtnWH*2, KKPraiseBtnWH*2*KKToBrokenHeartWH)];   _cancelPraiseImg.hidden = YES;   _cancelPraiseImg.centerX = _praiseBtn.centerX;   [self.view addSubview:_cancelPraiseImg]; } -(void)clickTheBtn:(UIButton *)btn {   [self playAnimation];   btn.userInteractionEnabled = NO;   btn.selected = !btn.selected; } -(void)playAnimation{   if (!_praiseBtn.selected) {     _coverBtn.alpha = 1;     [UIView animateWithDuration:1.0f animations:^{       _coverBtn.frame = CGRectMake(80, 100, KKPraiseBtnWH*2, KKPraiseBtnWH*2);       CAKeyframeAnimation *anima = [CAKeyframeAnimation animationWithKeyPath:@"transform.rotation"];       NSValue *value1 = [NSNumber numberWithFloat:-M_PI/180*5];       NSValue *value2 = [NSNumber numberWithFloat:M_PI/180*5];       NSValue *value3 = [NSNumber numberWithFloat:-M_PI/180*5];       anima.values = @[value1,value2,value3];       anima.repeatCount = MAXFLOAT;       [_coverBtn.layer addAnimation:anima forKey:nil];       _coverBtn.alpha = 0;       _coverBtn.centerX = _praiseBtn.centerX;     } completion:^(BOOL finished) {       _coverBtn.frame = _praiseBtn.frame;       _praiseBtn.userInteractionEnabled = YES;     }];   } else {     _cancelPraiseImg.hidden = NO;     NSArray *imgArr = [NSArray arrayWithObjects:[UIImage imageNamed:@"icon_like_broken1"],[UIImage imageNamed:@"icon_like_broken2"],[UIImage imageNamed:@"icon_like_broken3"],[UIImage imageNamed:@"icon_like_broken4"], nil nil];     _cancelPraiseImg.animationImages = imgArr;     _cancelPraiseImg.animationDuration = KKBorkenTime;     _cancelPraiseImg.animationRepeatCount = 1;     [_cancelPraiseImg startAnimating];     [UIView animateWithDuration:KKBorkenTime animations:^{       _cancelPraiseImg.frame = CGRectMake(80, 200, KKPraiseBtnWH*2, KKPraiseBtnWH*2*KKToBrokenHeartWH);       _cancelPraiseImg.alpha = 0;     }completion:^(BOOL finished) {       _cancelPraiseImg.frame = CGRectMake(80, 150, KKPraiseBtnWH*2, KKPraiseBtnWH*2*KKToBrokenHeartWH);       _cancelPraiseImg.alpha = 1;       _praiseBtn.userInteractionEnabled = YES;     }];   } }</span>