AVPlayerItem Swift 2 无检查

Question

代码在 Swift 1.2 中运行良好，但是当我更改 Xcode 7 (Swift 2) 时，出现错误，如下所示 if 语句。

let objFirstSound = AVPlayerItem(URL:NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource(self.objVowels?.main_sound, ofType: "mp3") ?? ""))

if objFirstSound != nil {
   arrTemp.append(objFirstSound)
}

Binary operator '!=' cannot be applied to operands of type 'AVPlayerItem' and 'NilLiteralConvertible'

那么，我如何检查 AVPlayerItem 实际上是 Nil？

Answer 1

您可以声明一个可选的：

let objFirstSound : AVPlayerItem? = AVPlayerItem(URL:NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource(self.objVowels?.main_sound, ofType: "mp3") ?? ""))

然后做：

if let objFirstSound = objFirstSound
{
    arrTemp.append(objFirstSound)
}

AVPlayerItem Swift 2 无检查

AVPlayerItem Swift 2 Nil Checking

avfoundation

swift

avplayeritem

xcode7

swift2