iOS Swift視頻全屏播放實現效果

一、需求小屏切全屏，全屏再切換小屏原來位置

從小屏進入全屏時，將播放器所在的view放置到window上，用transform的方式作一個旋轉動畫，最終讓view徹底覆蓋window。 從全屏回到小屏時，用transform的方式作旋轉動畫，最終讓播放器所在的view回到原先的parentView上

//進入全屏模式
func enterFullScreen() {
    self.smallPreViewFrame = self.preView.frame
    let rectInWindow = self.preView.convert(self.preView.bounds, to: UIApplication.shared.keyWindow)
    self.preView.removeFromSuperview()
    self.preView.frame = rectInWindow
    UIApplication.shared.keyWindow?.addSubview(self.preView)
    
    UIView.animate(withDuration: 0.5, animations: {
        self.preView.transform = self.preView.transform.rotated(by: .pi / 2)
        self.preView.bounds = CGRect(x: 0, y: 0, width: max(kScreenWidth, kScreenHeight), height: min(kScreenWidth, kScreenHeight))
        self.preView.center = CGPoint(x: self.preView.superview!.bounds.midX, y: self.preView.superview!.bounds.midY)
    }) { (isFinished) in
        
    }
}


//退出全屏
func exitFullScreen() {
    let frame = self.view.convert(self.smallPreViewFrame, to: UIApplication.shared.keyWindow)
    
    UIView.animate(withDuration: 0.5, animations: {
        self.preView.transform = CGAffineTransform.identity
        self.preView.frame = frame
    }) { (isFinished) in
        // 回到小屏位置
        self.preView.removeFromSuperview()
        self.preView.frame = self.smallPreViewFrame
        self.view.addSubview(self.preView)
    }
}