swift - 调用touchesEnded时移除 View

Question

当用户触摸并按住手指在屏幕上时，我使用touchesBegan在屏幕上添加 View

参见下面的示例

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            let location = touch.location(in: view)
            let dot = CustomTouch(frame: CGRect(x: location.x, y: location.y, width: 80, height: 80))
            dot.backgroundColor = randomColors[0]
            self.view.addSubview(dot)
        }
    }

我想检测用户何时从屏幕上抬起手指，然后删除在该位置添加的 View 。我想要一些关于如何实现这一目标的想法

Answer 1

为添加的 View 添加一个属性，而不是动态创建，然后删除(如果在 TouchsEnded 上存在的话):

var dot: CustomTouch?

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let location = touch.location(in: view)
        dot = CustomTouch(frame: CGRect(x: location.x, y: location.y, width: 80, height: 80))
        dot.backgroundColor = randomColors[0]
        self.view.addSubview(dot)
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    dot?.removeFromSuperview()
}