利用 CAKeyframeAnimation实现任意轨迹移动
![](https://img2018.cnblogs.com/blog/556239/201907/556239-20190729110110534-1248085321.gif)
自定义 View,实现以下方法即可
- (void)drawRect:(CGRect)rect {
// Drawing code
// 初始化UIBezierPath
UIBezierPath *path = [UIBezierPath bezierPath];
// 首先设置一个起始点
/////左半边曲线
CGPoint startPoint = CGPointMake(rect.size.width/2, rect.size.height*0.4);
// 以起始点为路径的起点
[path moveToPoint:startPoint];
// 设置一个终点
CGPoint endPoint = CGPointMake(rect.size.width/2, rect.size.height- rect.size.height*0.1);
// 设置第一个控制点
CGPoint controlPoint1 = CGPointMake(self.bounds.size.width*0.1, rect.size.height*0.1);
// 设置第二个控制点
CGPoint controlPoint2 = CGPointMake(0, self.size.height*0.7);
// 添加三次贝塞尔曲线
[path addCurveToPoint:endPoint controlPoint1:controlPoint1 controlPoint2:controlPoint2];
// 设置另一个起始点
[path moveToPoint:endPoint];
//右半边曲线>>>>>>>>>>>>>>>>>>>>
// 设置第三个控制点
CGPoint controlPoint3 = CGPointMake(rect.size.width-self.bounds.size.width*0.1, rect.size.height*0.1);
// 设置第四个控制点
CGPoint controlPoint4 = CGPointMake(rect.size.width, self.size.height*0.7);
// 添加三次贝塞尔曲线
[path addCurveToPoint:startPoint controlPoint1:controlPoint4 controlPoint2:controlPoint3];
// 设置线宽
path.lineWidth = 3;
// 设置线断面类型
path.lineCapStyle = kCGLineCapRound;
// 设置连接类型
path.lineJoinStyle = kCGLineJoinRound;
// 设置画笔颜色
[[UIColor redColor] set];
[path stroke];
UIView *heart = [[UIView alloc] init];
heart.frame = CGRectMake(0, 0, 20 , 20);
heart.backgroundColor =[UIColor redColor];
[self addSubview:heart];
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
// 设置动画的路径为心形路径
animation.path = path.CGPath;
// 动画时间间隔
animation.duration = 3.0f;
// 重复次数为最大值
animation.repeatCount = FLT_MAX;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
//设置加速度
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
// 将动画添加到动画视图上
[heart.layer addAnimation:animation forKey:nil];
}
Demo地址:https://github.com/yuying2012/WJDStudyLibrary
这是一个大工程,请从工程中寻找相关模块代码.