iOS添加購物車動畫效果示例

2020-07-26 02:55:19

字體：大中小

來源：轉載

供稿：網友

一、計算動畫開始結束點位置

方法：

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

1）動畫開始位置fromCenter

復制代碼代碼如下:

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

2）動畫結束位置endCenter

復制代碼代碼如下:

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

二、計算貝塞爾曲線（拋物線）的兩個控制點

controlPoint1是控制點1
controlPoint2是控制點2
A是controlPoint1和controlPoint2的中點
controlPointC是fromCenter和B的中點

1）先設置控制點距最高點（fromCenter或endCenter）的水平距離controlPointEY，本篇默認controlPointEY = 100，即圖1中點controlPointC到點A的距離。

2）計算控制點相對于點A的距離controlPointEX，即controlPoint1到A距離或controlPoint2到A距離，本篇設置為fromCenter.x到endCenter.x的1/4，即controlPointEX = (endCenter.x - fromCenter.x) * 0.25f;

3）計算兩個控制點

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

三、復制動畫的layer

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

四、動畫組合

1）運動軌跡（拋物線）

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

2）旋轉起來

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）縮放動畫

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

4）透明度動畫

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

5）動畫組合

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"];

動畫效果：