无法将值类型“”转换为预期的参数“UInt64”

Question

我在从 Swift 2 转换到 Swift 3 后立即使用了这段代码，然后出现了这个错误消息。任何帮助将不胜感激。我对 Swift 3 很陌生。

func checkIfCorrect (_ buttonPressed:Int) {
    if buttonPressed == playlist[numberOfTaps] {
        if numberOfTaps == playlist.count - 1 { // we have arrived at the last item of the playlist

            let time = DispatchTime(uptimeNanoseconds: DispatchTime.now()) + Double(Int64(NSEC_PER_SEC)) / Double(NSEC_PER_SEC)

            DispatchQueue.main.asyncAfter(deadline: time, execute: { 
                    self.nextRound()
            })

            return
        }

        numberOfTaps += 1
    }else{ // GAME OVER
        resetGame()
    }
}

Answer 1

你有这个：

let time = DispatchTime(uptimeNanoseconds: DispatchTime.now()) + Double(Int64(NSEC_PER_SEC)) / Double(NSEC_PER_SEC)

这样写：

let time = DispatchTime.now() + 1.0 // or however long you want the delay to be