Swift：每次触摸屏幕时，如何更改背景的位置？

Question

我希望我的背景节点在每次触摸屏幕时向下移动50个像素。

编辑：答：我有两个节点背景相同的背景，每次触摸屏幕时，背景向下移动50个像素。

if bg.position.y + bg.size.height/2 < 50 
    { 
     let diff = bg.position.y + bg.size.height/2 - 50 
     bg.position.y = self.frame.height + bg.size.height/2 + diff 
    } 
    else 
    { 
     bg.position.y -= 50 
    } 
    if bg2.position.y + bg2.size.height/2 < 50 
    { 
     let diff = bg2.position.y + bg2.size.height/2 - 50 
     bg2.position.y = self.frame.height + bg2.size.height/2 + diff 
    } 
    else 
    { 
     bg2.position.y -= 50 
    } 

Answer 1

改变你的背景位置？

background.position.y += 50.0