iOS实现数字倍数动画效果

来源：jb51　　时间：2019/3/1 8:59:51　　对本文有异议

前言

一个简单的利用透明度和缩放实现的数字倍数动画

效果图：

实现思路

上代码看比较清晰

// 数字跳动动画
- (void)labelDanceAnimation:(NSTimeInterval)duration {
 //透明度
 CABasicAnimation *opacityAnimation = [CABasicAnimation animationWithKeyPath:@"opacity"];
 opacityAnimation.duration = 0.4 * duration;
 opacityAnimation.fromValue = @0.f;
 opacityAnimation.toValue = @1.f;
 
 //缩放
 CAKeyframeAnimation *scaleAnimation = [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
 scaleAnimation.duration = duration;
 scaleAnimation.values = @[@3.f, @1.f, @1.2f, @1.f];
 scaleAnimation.keyTimes = @[@0.f, @0.16f, @0.28f, @0.4f];
 scaleAnimation.removedOnCompletion = YES;
 scaleAnimation.fillMode = kCAFillModeForwards;
 
 CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
 animationGroup.animations = @[opacityAnimation, scaleAnimation];
 animationGroup.duration = duration;
 animationGroup.removedOnCompletion = YES;
 animationGroup.fillMode = kCAFillModeForwards;
 
 [self.comboLabel.layer addAnimation:animationGroup forKey:@"kComboAnimationKey"];
}

利用一个透明度从 0 ~ 1之间的alpha,然后缩放之后加到动画组实现一下就好了

切记动画完成最好移除否则可能引起动画内存问题

这里设置斜体字体

self.comboLabel.font = [UIFont fontWithName:@"AvenirNext-BoldItalic" size:50];

看着比较明显

最后按钮点击的时候调用

- (IBAction)clickAction:(UIButton *)sender {
 self.danceCount++;
 [self labelDanceAnimation:0.4];
 self.comboLabel.text = [NSString stringWithFormat:@"+ %tu",self.danceCount];
}