嵌套的CAShapeLayer §获取原点？

Question

for (CALayer *layer in self.view.layer.sublayers) {
    if ([layer isKindOfClass:[CAShapeLayer class]]) {
        CAShapeLayer *copy = (CAShapeLayer *)layer;
        if ([copy.name isEqualToString:@"datumSideLayer"]) {
            //get start position, get height, get width
            CGPoint startPos = copy.frame.origin;
            float width = copy.frame.size.width;
            float height = copy.frame.size.height;
            CGPoint startPoint = CGPointMake(startPos.x + (width/2), startPos.y);
            CGPoint endPoint = CGPointMake(startPos.x + (width/2), startPos.y + height);
            NSLog(@"%.1f:%.1f, %.1f:%.1f", startPoint.x, startPoint.y, endPoint.x, endPoint.y);
            [self drawDashedLineFrom:startPoint toEnd:endPoint inView:_thicknessUI];
            break;
        }
    }
}

NSLog 输出0.0:0.0, 0.0:0.0 。

它嵌套的形状层被强实例化为属性。但是，我无法从框架中抓取原点，宽度或高度。

编辑：经过进一步挖掘，我没有为我的CAShapeLayer设置框架 - 因为它是由路径绘制的。

但是，我现在如何才能适应它，以便能够从路径的起点抓住它的起源？

[path moveToPoint:CGPointMake(self.view.frame.size.width/2 - _plateLengthPX, tenPercent)]; // datum side start
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - capStartWidthPX - rootGapPX, tenPercent)]; // weld(cap) start
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - rootGapPX, tenPercent + _plateHeightPX - rootPrepHeightPX)]; // weld(root prep) start
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - rootGapPX, tenPercent + _plateHeightPX)]; // weld(root prep) end
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - _plateLengthPX, tenPercent + _plateHeightPX)]; // datum side end
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - _plateLengthPX, tenPercent + _plateHeightPX/2 + 10)]; // datum side end
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - _plateLengthPX + 15, tenPercent + _plateHeightPX/2 + 5)]; // datum side end
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - _plateLengthPX - 15, tenPercent + _plateHeightPX/2 - 5)]; // datum side end
[path addLineToPoint:CGPointMake(self.view.frame.size.width/2 - _plateLengthPX, tenPercent + _plateHeightPX/2 - 10)]; // datum side end
_datumLayer = [CAShapeLayer layer];
_datumLayer.name = @"datumSideLayer";
_datumLayer.path = [path CGPath];
_datumLayer.strokeColor = [_lineColor CGColor];
_datumLayer.lineWidth = 2.0;
_datumLayer.fillColor = [_shaderColor CGColor];
[self.view.layer addSublayer:_datumLayer];

Answer 1

好的，

我已经设法深入挖掘以找到我的问题的原因。

原因是未设置 CAShapeLayer 的帧和原点，因此无法强制转换 §GET 来检索其值。但是，在实例化属性时，您可以设置相对于所用路径的位置和边界。

CGRect pathRect = CGPathGetPathBoundingBox([path CGPath]);
_datumLayer.bounds = pathRect;
_datumLayer.position = CGPointMake(CGRectGetMidX(pathRect), CGRectGetMidY(pathRect));