MPRemoteCommandCenter禁用了所有控件

Question

您好，亲爱的同事，我需要您的帮助。当我添加MPChangePlaybackPositionCommand时，我所有的控件（锁定屏幕上的“播放/暂停/倒退/下一首”曲目）都已自动禁用。锁定屏幕上的“播放”滑块可完美运行，但我无法按任何一个控制按钮来说明为什么-我不知道。

我也尝试过这个：

[[MPRemoteCommandCenter sharedCommandCenter].playCommand setEnabled:YES];
[[MPRemoteCommandCenter sharedCommandCenter].pauseCommand setEnabled:YES];
[[MPRemoteCommandCenter sharedCommandCenter].previousTrackCommand setEnabled:YES];
[[MPRemoteCommandCenter sharedCommandCenter].nextTrackCommand setEnabled:YES]; 

我的代码非常简单：

 MPChangePlaybackPositionCommand *changePlaybackPositionCommand = [[MPRemoteCommandCenter sharedCommandCenter] changePlaybackPositionCommand];
    [changePlaybackPositionCommand addTarget:self action:@selector(onChangePlaybackPositionCommand:)];

- (MPRemoteCommandHandlerStatus) onChangePlaybackPositionCommand:
(MPChangePlaybackPositionCommandEvent *) event

{
    [[[PlayerPlistController utilise]miniplayer] seekToTime:CMTimeMakeWithSeconds(event.positionTime, 1)];

    NSLog(@"changePlaybackPosition to %f", event.positionTime);

    return MPRemoteCommandHandlerStatusSuccess;
}

NSMutableDictionary *songInfo = [[NSMutableDictionary alloc] init];

[songInfo setObject:NAME_TITLE forKey:MPMediaItemPropertyTitle];
[songInfo setObject:NAME_TITLE_SLOGON forKey:MPMediaItemPropertyAlbumTitle];

UIImage *image = [UIImage imageNamed:PLACEHOLDER_EMPTY];
MPMediaItemArtwork *imageArt =  [[MPMediaItemArtwork alloc] initWithBoundsSize:image.size requestHandler:^UIImage* _Nonnull(CGSize aSize) { return image; }];

[songInfo setObject:imageArt forKey:MPMediaItemPropertyArtwork];
[[MPNowPlayingInfoCenter defaultCenter] setNowPlayingInfo:songInfo];

Answer 1

让我们以“播放/暂停”按钮为例。 启用是不够的。您还必须实现（我为在Swift中编写代码表示歉意；我懒得将其转换回Objective-C，但您肯定可以理解这一点）：

let mprc = MPRemoteCommandCenter.shared()
mprc.playCommand.addTarget(self, action:#selector(doPlay))
mprc.pauseCommand.addTarget(self, action:#selector(doPause))

等，以及实际的doPlay和doPause实现。