ios - 检测 CAShapeLayer 触摸

Question

我通过覆盖绘制矩形创建了一个蜘蛛图，我正在使用核心图形 CAShapeLayer 来绘制我的区域，在屏幕上创建了多个 CAShapeLayer 区域，我想检测用户触摸时触摸了哪个图层......但是我想不通怎么办？

Answer 1

首先，您不应该在 drawRect 中绘制图层，但这不是您的问题。要识别“触摸”的图层，您可以执行以下操作...

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    for (UITouch *touch in touches) {
        CGPoint touchLocation = [touch locationInView:self.view];
        for (id sublayer in self.view.layer.sublayers) {
            BOOL touchInLayer = NO;
            if ([sublayer isKindOfClass:[CAShapeLayer class]]) {
                CAShapeLayer *shapeLayer = sublayer;
                if (CGPathContainsPoint(shapeLayer.path, 0, touchLocation, YES)) {
                    // This touch is in this shape layer
                    touchInLayer = YES;
                }
            } else {
                CALayer *layer = sublayer;
                if (CGRectContainsPoint(layer.frame, touchLocation)) {
                    // Touch is in this rectangular layer
                    touchInLayer = YES;
                }
            }
        }
    }
}

Answer 2

为了快速回答，这是在触摸开始时的 beginTracking，您还可以实现 continueTracking 以防您要继续跟踪什么。

它是如何工作的，您在 beginTracking 中获取触摸位置并检查，您的图层框架包含您触摸的点，如果是，它将打印语句。同样的方式你可以检查你的所有图层

override open func beginTracking(_ touch: UITouch, with event: UIEvent?) -> Bool {
     let loaction = touch.location(in: self)
     //update yourLayer with your layer name
     if yourLayer.frame.contains(previousLoaction) { 
        Print("Touch is inside yourLayer layer")
     }
}