Swift3 使用CGEvent从键码中快速获取字符

我有一个关键代码，来自：

let keycode = event.GetIntegerValueField(.keyboardEventKeycode)

有没有办法把它翻译成一个角色

func keyboardGetUnicodeString(maxStringLength: Int, actualStringLength: UnsafeMutablePointer <Int>?, unicodeString: UnsafeMutablePointer <UniChar>?)

func键盘GetUnicodestring（maxStringLength:Int，actualStringLength:UnsafeMutablePointer？，unicodeString:UnsafeMutablePointer？）

这似乎是我需要的，但看起来很可怕！有人能解释一下如何从swift调用该函数吗？谢谢

var char = UniChar()
var length = 0
event.keyboardGetUnicodeString(maxStringLength: 1, actualStringLength: &length, unicodeString: &char)