如何在Swift 4中使用Swift 3的已废弃语法

Question

录制视频,同时设置视频编解码器如下:

sessionOutput.outputSettings = [AVVideoCodecKey: AVVideoCodecTypeJPEG]

XCode中说,'AVVideoCodecTypeJPEG' has been renamed to 'AVVideoCodecType.jpeg'与'AVVideoCodecTypeJPEG' was obsoleted in Swift 3它暗示Replace 'AVVideoCodecTypeJPEG' with 'AVVideoCodecType.jpeg'

在这之后,XCode说'jpeg' is only available on iOS 11.0 or newer.

问题是我必须使用iOS 10并且想要使用Swift 4.

有没有任何解决方案可以在iOS 10的Swift 4中使用这样的功能？

Answer 1

我认为解决此类问题的正确方法是使用新的AVVideoCodecType.jpeg和已弃用的方法AVVideoCodecJPEG,这样做:

if #available(iOS 11.0, *) {
    sessionOutput.outputSettings = [AVVideoCodecKey: AVVideoCodecType.jpeg]
} else {
    sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]
}