爲什麼我的touchesEnded函數沒有初始化？

Question

該代碼將返回x1和y1值，但似乎沒有通過touchesEnded函數運行。我的目標是創建一個矩形，從用戶觸摸的角落開始，並在用戶舉起手指的地方結束。

  //touch initialized 
      override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { 
      for touch in touches { 
      let location = touch.location(in: self) 
      let x1 = location.x 
      let y1 = location.y 
      print(x1,y1) 

     } 

      func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?){ 
      for touch in touches{ 

      let location2 = touch.location(in: self) 
      let x2 = location2.x 
      let y2 = location2.y 
      let originX = min(x1,x2) 
      let originY = min(y1,y2) 
      let cornerX = max(x1,x2) 
      let cornerY = max(y1,y2) 
      let boxWidth = cornerX - originX 
      let boxHeight = cornerY - originY 

      let box = SKSpriteNode() 
      box.size = CGSize(width: boxWidth, height: boxHeight) 
      box.color = SKColor.black 
      box.position = CGPoint(x:originX, y: originY) 
      addChild(box) 

      print(x1,y1,x2,y2) 
      } 
      } 

Answer 1

在你的代碼的問題是，它缺少一個大括號關閉touchesBegan，所以touchesEnded是不允許被覆蓋，因爲它在技術上你touchesBegan而非場景本身。

試試這個：

var x1: CGFloat = 0.0 
var y1: CGFloat = 0.0 

//... 

//touch initialized 
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { 
    for touch in touches { 
     let location = touch.location(in: self) 
     x1 = location.x 
     y1 = location.y 
     print(x1,y1) 
    } 
} 

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

    for touch in touches{ 
     let location2 = touch.location(in: self) 
     let x2 = location2.x 
     let y2 = location2.y 
     let originX = min(x1,x2) 
     let originY = min(y1,y2) 
     let cornerX = max(x1,x2) 
     let cornerY = max(y1,y2) 
     let boxWidth = cornerX - originX 
     let boxHeight = cornerY - originY 
     let box = SKSpriteNode() 
     box.size = CGSize(width: boxWidth, height: boxHeight) 
     box.color = SKColor.black 
     box.position = CGPoint(x:originX, y: originY) 
     addChild(box) 

     print(x1,y1,x2,y2) 
    } 
} 

當然，而不是保存每個x和y座標分別，我想突出部分儲存2個CGPoints