iOS 控制中心音乐控件在 iOS 11 更新中停止工作（remoteControlReceivedWithEvent 不称为 iOS 11）

Question

iOS 控制中心的音乐控件出现问题 在 iOS 11 更新之前，播放暂停按钮已启用并正常工作，正如预期的那样。

但是，在 iOS 11 中，它停止了工作。经过研究，我发现在 IOS 11 中 remoteControlReceivedWithEvent 永远不会被调用，但是在 iOS 9 等旧版 iOS 中它会被正常调用

我将我的事件设置在AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  // Enable background audio listening
    // https://developer.apple.com/library/ios/qa/qa1668/_index.html
    NSError *error = nil;
    if (![[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&error]) {
        NSLog(@"%@", error);
    }
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
}


- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent {
    if (receivedEvent.type == UIEventTypeRemoteControl) {
        switch (receivedEvent.subtype) {
            case UIEventSubtypeRemoteControlPlay:
                [[NSNotificationCenter defaultCenter] postNotificationName:kCYCAppDelegatePlayPauseNotificationName object:nil];
                break;
            case UIEventSubtypeRemoteControlPause:
                [[NSNotificationCenter defaultCenter] postNotificationName:kCYCAppDelegatePlayPauseNotificationName object:nil];
                break;
            case UIEventSubtypeRemoteControlTogglePlayPause:
                [[NSNotificationCenter defaultCenter] postNotificationName:kCYCAppDelegatePlayPauseNotificationName object:nil];
                break;
            default:
                break;
        }
    }
}

我还订阅了另一个类中的远程事件来控制播放/暂停按钮

- (void)subscribeToRemoteControlEvents {

    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.1")) {
        // Disables the forward/backward buttons and only shows the play button.
        // You can't just enable the command, you must subscribe for this to activate, so
        // the subscription in this case doesn't do anything.
        [MPRemoteCommandCenter sharedCommandCenter].togglePlayPauseCommand.enabled = YES;
        [[MPRemoteCommandCenter sharedCommandCenter].togglePlayPauseCommand addTarget:self action:@selector(ignore_removeCommandCenterFired)];
    }

    [[NSNotificationCenter defaultCenter] addObserver:self forName:kCYCAppDelegatePlayPauseNotificationName object:nil queue:nil usingBlock:^(NSNotification *note, CYCCastManager *observer) {
        if (observer.isCastPlaying) {
            [observer pause];
        }
        else {
            [observer play:NO];
        }
    }];
}

- (void)unsubscribeFromRemoteControlEvents {
    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.1")) {
        [[MPRemoteCommandCenter sharedCommandCenter].togglePlayPauseCommand removeTarget:self action:@selector(ignore_removeCommandCenterFired)];
    }
}

我想知道为什么不再工作我确实检查了文档以了解 API 的更改，但我没有看到更改

注意：我没有运气检查以下链接

iOS - UIEventTypeRemoteControl events not received

https://forums.developer.apple.com/thread/84204

Unable to receive remoteControlReceivedWithEvent - objective c - ios

remoteControlReceivedWithEvent in AVAudio is not being called

remoteControlReceivedWithEvent not Called in appDelegate

Answer 1

最后我通过使用 remoteCommandCenter 和播放和暂停按钮而不是 tooglePlayPauseCommand 解决了这个问题

if(SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"11.0")){
    //NOTE: this is the only way that I find to make this work on IOS 11 its seems to be that togglePlayPauseCommand is not working anymore
    MPRemoteCommandCenter* commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
    [commandCenter.playCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        [[NSNotificationCenter defaultCenter] postNotificationName:kCYCAppDelegatePlayNotificationName object:nil];
        return MPRemoteCommandHandlerStatusSuccess;
    }];

    [commandCenter.pauseCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        [[NSNotificationCenter defaultCenter] postNotificationName:kCYCAppDelegatePauseNotificationName object:nil];
        return MPRemoteCommandHandlerStatusSuccess;
    }];

    [[NSNotificationCenter defaultCenter] addObserver:self forName:kCYCAppDelegatePlayNotificationName object:nil queue:nil usingBlock:^(NSNotification *note, CYCCastManager *observer) {
        if (!observer.isCastPlaying) {
            [observer play:NO];
        }
    }];

    [[NSNotificationCenter defaultCenter] addObserver:self forName:kCYCAppDelegatePauseNotificationName object:nil queue:nil usingBlock:^(NSNotification *note, CYCCastManager *observer) {
        if (observer.isCastPlaying) {
            [observer pause];
        }
    }];


}

Answer 2

刚刚被胡安的回答修改了。

if(@available(iOS 11, *)) {
    MPRemoteCommandCenter* commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
    [commandCenter.playCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {

        [[NSNotificationCenter defaultCenter] postNotificationName:@"RemotePlayCommandNotification" object:nil];
        return MPRemoteCommandHandlerStatusSuccess;
    }];

    [commandCenter.pauseCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        [[NSNotificationCenter defaultCenter] postNotificationName:@"RemotePauseCommandNotification" object:nil];
        return MPRemoteCommandHandlerStatusSuccess;
    }];

    [[NSNotificationCenter defaultCenter] addObserverForName:@"RemotePlayCommandNotification" object:nil queue:nil usingBlock:^(NSNotification * _Nonnull note) {

        NSLog(@"Clicked the play button.");
    }];

    [[NSNotificationCenter defaultCenter] addObserverForName:@"RemotePauseCommandNotification" object:nil queue:nil usingBlock:^(NSNotification * _Nonnull note) {

        NSLog(@"Clicked the pause button.");
    }];

}