swift - Touchesmoved - 单次拖动更新多个元素

Question

我正在尝试通过单击并拖动元素来更新多个图像。我已经实现了 touchesbegan、touchesmoved 和 touchesended，但我不知道如何使 touchesmoved 影响多个图像。

我一直在网上搜索，但没能找到这方面的任何指南。如果您能为我指明正确的方向，或为我提供一些基本建议，将不胜感激。

以下是示例图片:

编辑:以下是应该可能的示例图像:

What it should look like.

我希望能够通过相同的按压以相同的方式影响其他字母，改变它们的图片。这些图片是临时图片。

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    print("touches began:\(touches)")
}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
            self.image = UIImage(named: "slot")!
        print("touches moved:\(touches)")
    }

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        self.image = UIImage(named: "tile")!
        print("touches ended")
    }

Answer 1

如果我没理解错的话，应该是这样的:

class ChangableView: UIView {
    private var touchedImageView: UIImageView? {
        didSet {
            if oldValue == touchedImageView { return }
            if let oldValue = oldValue {
                oldValue.image = UIImage(named: "tile")!
            }
            if let newValue = touchedImageView {
                newValue.image = UIImage(named: "slot")!
            }  
        }
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        guard let touch = touches.first else { return }
        updateTouchedImageViewWithTouch(touch, event: event)
    }

    override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
        guard let touch = touches.first else { return }
        updateTouchedImageViewWithTouch(touch, event: event)
    }

    override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
        touchedImageView = nil
    }
}

private extension ChangableView {
    func updateTouchedImageViewWithTouch(touch: UITouch, event: UIEvent?) {
        let touchPoint = touch.locationInView(self)
        let touchedView = self.hitTest(touchPoint, withEvent: event)
        touchedImageView = touchedView as? UIImageView
    }
}

此外，您的 UIViewController 应该具有 ChangableView 的子类 View ，并且不要忘记将所有 UIImageView 的 userInteractionEnabled 属性设置为 YES。