ios - 在 swift 中使用 PHImageManager (requestAVAssetForVideo)

Question

我正在使用 objective-c 图像选择器图像选择器来选择时间流逝，但我正在快速进行。我只能访问 objective-c 代码，所以我使用了 objective-c 到 swift 转换器，但出现错误。

func qb_imagePickerController(imagePickerController: QBImagePickerController, didFinishPickingAssets assets: [AnyObject]) {
    for asset in assets as! [PHAsset] {
        PHImageManager.defaultManager().requestAVAssetForVideo(asset, options: nil, resultHandler: {(avAsset: AVAsset, audioMix: AVAudioMix, info: [NSObject : AnyObject]) -> Void in
            var url: NSURL = NSURL(string: "\(asset)")!
            var avAsset: AVURLAsset = AVURLAsset(URL: url, options: nil)
            var playerItem: AVPlayerItem = AVPlayerItem(asset: avAsset)
            var videoPlayer: AVPlayer = AVPlayer(playerItem: playerItem)
            videoPlayer.play()
        })
    }
    self.dismissViewControllerAnimated(true, completion: { _ in })
}

这是我目前的代码。我收到的错误如下。

Cannot convert value of type '(AVAsset, AVAudioMix, [NSObject : AnyObject]) -> Void' to expected argument type '(AVAsset?, AVAudioMix?, [NSObject : AnyObject]?) -> Void'

Answer 1

查看 requestAVAssetForVideo:options:resultHandler: 的文档 您拥有的 resultHandler 与所需的签名不匹配。

改变这一行:

PHImageManager.defaultManager().requestAVAssetForVideo(asset, options: nil, resultHandler: {(avAsset: AVAsset, audioMix: AVAudioMix, info: [NSObject : AnyObject]) -> Void in

到:

PHImageManager.defaultManager().requestAVAssetForVideo(asset, options: nil, resultHandler: {(avAsset: AVAsset?, audioMix: AVAudioMix?, info: [NSObject : AnyObject]?) -> Void in

注意在预期位置添加 ?。