swift - 为什么 TouchBegan 不能正常工作？

Question

我有一个图像需要拖动到另一个图像的顶部。当您触摸它时，仅当您触摸图像顶部或其正上方的图像时，touchesBegan 才会注册。触摸图像的中心或顶部以外的任何其他部分根本没有任何作用。我设置正确了吗？

override func viewDidLoad() {
    super.viewDidLoad()
    imageView.image = selectedPhoto
    watermarkImageView.image = selectedWatermark
}

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    for touch in touches {
        let location = touch.locationInView(self.view)
        if watermarkImageView.frame.contains(location) {
            watermarkImageView.center = location
        } 
    } 
}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
    for touch in touches {
        let location = touch.locationInView(self.view)
        if watermarkImageView.frame.contains(location) {
            watermarkImageView.center = location
        } 
    }
}

Answer 1

两个 ImageView 都嵌套在另一个 View 内。我必须更改位置以反射(reflect)这一点。

let location = touch.locationInView(imageContainerView)