0
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斯威夫特 - animateWithDuration完成不好的訪問