ios - 使用核心动画为 StrokeColor 设置动画

Question

我正在尝试为 CAShapeLayar 的 strokeColor 属性设置动画。我查看了文档，并指出它是一个可动画的属性。该代码用于动画 postion.y 但不是 strokeColor。我很乐意获得任何帮助或建议

我用过的代码:

lyr.fillColor = [[UIColor clearColor] CGColor];
lyr.lineWidth = 3.8;
lyr.strokeColor = [[UIColor yellowColor] CGColor];
lyr.position = CGPointMake(160, 431);
lyr.anchorPoint = CGPointMake(.5f, .5f);
[self.view.layer addSublayer:lyr];

CABasicAnimation *basicAnimation = [CABasicAnimation animationWithKeyPath:@"strokeColor"];
basicAnimation.fromValue = [lyr valueForKey:@"strokeColor"];



basicAnimation.toValue =[NSValue valueWithPointer:[[UIColor clearColor] CGColor]];


basicAnimation.duration = 2;
basicAnimation.repeatCount = 10;
basicAnimation.autoreverses = YES;
[lyr addAnimation:basicAnimation forKey:@"strokeColor"];

提前致谢，或者。

Answer 1

这应该有效，因为我刚刚测试过它:

CABasicAnimation *strokeAnim = [CABasicAnimation animationWithKeyPath:@"strokeColor"]; // I changed the animation pointer name, but don't worry.
basicAnimation.toValue = (id) [UIColor clearColor].CGColor; // Just get rid of the fromValue line, and just cast the CGColorRef to an id.
basicAnimation.duration = 2;
basicAnimation.repeatCount = 10;
basicAnimation.autoreverses = YES;
[lyr addAnimation:strokeAnim forKey:@"flashStrokeColor"]; // I like to name this key differently, so as not create confusion.

请注意，我从动画中删除了 fromValue 属性行，因为您需要与动画之前设置的 strokeColor 相同的值(它是多余的)。此外，我将 strokeColor 的 CGColorRef 转换为一个 id，这正是 toValue 属性想要的。