let paths = NSSearchPathForDirectoriesInDomains(
            .DocumentDirectory,.UserDomainMask,true)

        // NSString *documentsDirectory = [paths objectAtIndex:0];
        let documentsDirectory = paths[0] as String

        var filePath:String? = nil
        var fileNamePostfix = 0
        do {
            filePath =
            "\(documentsDirectory)/\(dateTimePrefix)-\(fileNamePostfix++).mp4"
        } while (NSFileManager.defaultManager().fileExistsAtPath(filePath))

我需要将其转换为NSURL以在self.fileOutput.startRecordingToOutputFileURL(< #outputFileURL：NSURL？#>，recordingDelegate：< #AVCaptureFileOutputRecordingDelegate？#>)方法中使用。

我试过filePath？ NSURL()但是不正确

谢谢！