如何在AVQueuePlayer中循环声音队列？

Question

I know multiple questions concerning the same issue exist, but after following this one's suggestions, I run into a couple of problems.

I have everything set up but I get to mach errors everytime I use kMTTimeZero.

soundQueue = [AVQueuePlayer queuePlayerWithItems:soundEmotions];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(playerItemDidReachEnd:)
                                                 name:AVPlayerItemDidPlayToEndTimeNotification
                                               object:[soundEmotions lastObject]];

Here's what I've done .

- (void)playerItemDidReachEnd:(NSNotification *)notification {
    // Do stuff here
    NSLog(@"End has been reached.");

    // Set it back to the beginning
    [soundQueue seekToTime:kCMTimeZero];

    //Replay
    [soundQueue play];

}

ERROR: Undefined symbols for architecture armv7: "_kCMTimeZero", referenced from: -[ViewController playerItemDidReachEnd:] in ViewController.o ld: symbol(s) not found for architecture armv7 clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

kCMTimeZero是CoreMedia.framework中的符号，因此您必须将此框架添加到目标的“构建阶段”中的“链接二进制库”部分。

Answer 2

I am using this approach to observe last item and then seek to kCMTimeZero

 override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        if keyPath == "currentItem" {

            print("Next Track...", currentTrackIndex)

            if currentTrackIndex > 0 {
                self.isPlaying = true
            }

            currentTrackIndex += 1
            if currentTrackIndex > playerQueue.items().count {
                currentTrackIndex = 0
                playerQueue.seek(to: kCMTimeZero)
            }
        }
    }

And then

private func observeTrackChanged(of player : AVQueuePlayer) {

        player.addObserver(self, forKeyPath: "currentItem", options: .new, context: nil)
    }