Swift - animateWithDuration 完成错误访问

Question

   let downFrame = CGRect(x: 0, y: ScreenSize.height, width: ScreenSize.width, height: ScreenSize.height-Constants.navBarHeight)

UIView.animateWithDuration(0.3, animations: {
      self.frame = self.downFrame
    },
    completion: nil)

Animation move view out of screen. Then crash in comletion

Answer 1

你的代码工作得很好

Self.downFrame 的值是多少？