CAShapeLayer hitTest touch

Question

我不明白为什么 CAShapeLayer 不响应 hitTest

这个函数总是去 // touches is outside

如何检测 CAShapeLayer 上的触摸？

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)事件
{

    currentPoint = [[touches anyObject] locationInView:self];

    for (CAShapeLayer *layer in self.layer.sublayers) {

        如果（层== shapeLayer）{

            if([层 hitTest:currentPoint])
            {
                // touche 在图层上
            }
            别的 {
                // 触摸在外面
            }

        }

    }

}

Answer 1

苦思冥想两天后，我能够生成这个奇怪的代码，看起来它可以正常工作！

目标是命中测试 CAShapeLayer。 CAShapeLayer 在屏幕上移动，因此形状不在固定位置。命中 CGPath currentPoint 并不简单。

随意添加任何输入...

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)事件
{

    CGPoint p = [[touches anyObject] locationInView:self];

    CGAffineTransform transf = CGAffineTransformMakeTranslation(-shapeLayer.position.x, -shapeLayer.position.y);

    if(CGPathContainsPoint(shapeLayer.path, &transf, p, NO)){

       // 触摸在形状内部
    }

}

Answer 2

见下文——覆盖 CAShapeLayers hitTest() 方法

    // CAShapeLayer path coordinates are relative to the layer
    // so when hit testing to see if the mouse click is inside the path
    // convert the point to layer coordinates like so
    // This assumes the received coordinates are in the layers superlayer coordinates
    // Usually so if they come from a mouse click

    override func hitTest(_ p: CGPoint) -> CALayer? {
        
        let lp = self.convert(p, from: superlayer)
        
        let result = path?.contains(lp) ?? false
        
        return result ? self : nil
            
    }

Answer 3

在您的 CAShapeLayer 子类中，您可以覆盖 contains(point:) 方法而不是覆盖 hitTest:

override func contains(_ p: CGPoint) -> Bool {
    let result = self.path?.contains(p) ?? false
    return result
}