CAShaperLayer的前景在初始点有变化吗？

Question

我已经在我的iOS演示应用程序中制作了这样的圆圈。

http://www.pastebin.ca/3119326

如下图所示

I want a needle shape crossing 90 degree to line which is being made. like below image, which I am unable to find via code.

如何实现这一点，任何建议。

感谢。

Answer 1

伪代码/真实代码，这里是布局如何工作，只是一个快速的样本：

一行：

UIBezierPath* bezierPath = UIBezierPath.bezierPath;
[bezierPath moveToPoint: CGPointMake(43.5, 30.5)];
[bezierPath addCurveToPoint: CGPointMake(166.5, 74.5) controlPoint1: CGPointMake(166.5, 74.5) controlPoint2: CGPointMake(166.5, 74.5)];
[UIColor.blackColor setStroke];
bezierPath.lineWidth = 1;
[bezierPath stroke];

CAShapeLayer * firstNameCorners = [CAShapeLayer layer];
[firstNameCorners setPath:bezierPath];
[[self.view layer] addSublayer:firstNameCorners];

运行旋转动画：

- (void)spinUntilYouThrowUp:(CAShapeLayer*)shapeLayer duration:(CGFloat)duration rotations:(CGFloat)rotations repeat:(float)repeat;
{
    CABasicAnimation* rotationAnimation;
    rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 * rotations * duration ];
    rotationAnimation.duration = duration;
    rotationAnimation.cumulative = YES;
    rotationAnimation.repeatCount = repeat;
    [shapeLayer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
}