ios - 激活/停用代码

Question

试图在 if whiteDotDist < centerRadius - whiteDotRadius 时获取代码执行它下面的所有代码都是事件的，并且当它下面的代码被执行时它再次变为非事件状态直到if whiteDotDist < centerRadius - whiteDotRadius。再次被执行。有点像一个循环，所以你必须从中心到 smallDot 继续往回走。很难通过计算机解释。更新它给我错误'二元运算符'<'不能应用于'CGFloat'和'Double'类型的操作数

@IBAction func handlePan(recognizer:UIPanGestureRecognizer) {
    let translation = recognizer.translation(in: self.view)
    if let view = recognizer.view {
        view.center = CGPoint(x:view.center.x + translation.x,
                              y:view.center.y + translation.y)
    }
    recognizer.setTranslation(CGPoint.zero, in: self.view)


    let centerRadius = 37.5
    let whiteDotRadius = 23.5 

    let whiteDotDist = hypot(center.center.x - whiteDot.center.x, center.center.y - whiteDot.center.y - whiteDot.center.y)

    if whiteDotDist < centerRadius - whiteDotRadius {
  resetTimer()   }
    if (whiteDot.frame.contains(smallDot.frame) && smallDot.image != nil) {
        addOne += 1
        score.text = "\(addOne)"

        resetTimer()

        timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(SecondViewController.startTimer), userInfo: nil, repeats: true)

        smallDot.center = spawnRandomPosition()  
    }
    }
    }

Answer 1

检查以确保:

1. 所有 View 都有相同的父 View (因此它们都在相同的坐标系中)

2. 框架紧紧围绕着圆圈。把center、whiteDot、smallDot的背景色改成红色，发个图

即使您这样做，您的代码也会检查边界矩形是否在彼此内部，因此它可能看起来像小点在白点之外(如果它在角落)，但边界框被白点的框架包围.

如果您想检查圆圈(不是边界框)是否在彼此内部，请获取中心之间的距离并确保它在(外半径 - 较小的点半径)内。

伪代码

   let centerRadius = 100 // set this to radius of center circle
   let whiteDotRadius = 10 // set this to whiteDot radius

   let whiteDotDist = hypotf(center.center.x - whiteDot.center.x, center.center.y - whiteDot.center.y)

   if whiteDotDist < centerRadius - whiteDotRadius {
      // whiteDot is inside center
   }