iOS添加购物车动画效果示例

2020-07-26 02:55:19

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一、计算动画开始结束点位置

方法：

- (CGPoint)convertPoint:(CGPoint)point toView:(nullable UIView *)view;

1）动画开始位置fromCenter

复制代码代码如下:

CGPoint fromCenter =  [animationView convertPoint:CGPointMake(animationView.frame.size.width * 0.5f, animationView.frame.size.height * 0.5f) toView:keyWindow];

2）动画结束位置endCenter

复制代码代码如下:

CGPoint endCenter = [endView convertPoint:CGPointMake(endView.frame.size.width * 0.5f, endView.frame.size.height * 0.5f) toView:keyWindow];

二、计算贝塞尔曲线（抛物线）的两个控制点

controlPoint1是控制点1
controlPoint2是控制点2
A是controlPoint1和controlPoint2的中点
controlPointC是fromCenter和B的中点

1）先设置控制点距最高点（fromCenter或endCenter）的水平距离controlPointEY，本篇默认controlPointEY = 100，即图1中点controlPointC到点A的距离。

2）计算控制点相对于点A的距离controlPointEX，即controlPoint1到A距离或controlPoint2到A距离，本篇设置为fromCenter.x到endCenter.x的1/4，即controlPointEX = (endCenter.x - fromCenter.x) * 0.25f;

3）计算两个控制点

CGPoint controlPoint1 = CGPointMake(controlPointCX - controlPointEX, controlPointCY - controlPointEY);CGPoint controlPoint2 = CGPointMake(controlPointCX + controlPointEX, controlPointCY - controlPointEY);

三、复制动画的layer

NSString *str = ((UIButton *)animationView).titleLabel.text;_animationLayer = [CATextLayer layer];_animationLayer.bounds = animationView.bounds;_animationLayer.position = fromCenter;_animationLayer.alignmentMode = kCAAlignmentCenter;//文字对齐方式_animationLayer.wrapped = YES;_animationLayer.contentsScale = [UIScreen mainScreen].scale;_animationLayer.string = str;_animationLayer.backgroundColor = [UIColor redColor].CGColor;[keyWindow.layer addSublayer:_animationLayer];

四、动画组合

1）运动轨迹（抛物线）

UIBezierPath *path = [UIBezierPath bezierPath];[path moveToPoint:fromCenter];[path addCurveToPoint:endCenter controlPoint1:controlPoint1 controlPoint2:controlPoint2];CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];pathAnimation.path = path.CGPath;

2）旋转起来

CABasicAnimation *rotateAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];rotateAnimation.removedOnCompletion = YES;rotateAnimation.fromValue = [NSNumber numberWithFloat:0];rotateAnimation.toValue = [NSNumber numberWithFloat:10 * M_PI];rotateAnimation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]

3）缩放动画

CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];scaleAnimation.removedOnCompletion = NO;scaleAnimation.fromValue = [NSNumber numberWithFloat:1.0];scaleAnimation.toValue = [NSNumber numberWithFloat:0.2];

4）透明度动画

CABasicAnimation *alphaAnimation = [CABasicAnimation animationWithKeyPath:@"opacity"];alphaAnimation.removedOnCompletion = NO;alphaAnimation.fromValue = [NSNumber numberWithFloat:1.0];alphaAnimation.toValue = [NSNumber numberWithFloat:0.1];

5）动画组合

CAAnimationGroup *groups = [CAAnimationGroup animation];groups.animations = @[pathAnimation,rotateAnimation, scaleAnimation, alphaAnimation];groups.duration = kShoppingCartDuration;groups.removedOnCompletion=NO;groups.fillMode=kCAFillModeForwards;groups.delegate = self;[_animationLayer addAnimation:groups forKey:@"group"];

动画效果：