iOS播放媒体库的音乐

1.申请媒体库使用权限

+ (BOOL)hasMediaLibraryAuth {

    MPMediaLibraryAuthorizationStatus aStatus = [MPMediaLibrary authorizationStatus];

    if (aStatus == MPMediaLibraryAuthorizationStatusNotDetermined) {

        [MPMediaLibrary requestAuthorization:^(MPMediaLibraryAuthorizationStatus status) {

            if (aStatus == MPMediaLibraryAuthorizationStatusAuthorized) {

                [self fetchItunsMusics];

            }

        }];

        return NO;

    }

    if (aStatus == MPMediaLibraryAuthorizationStatusAuthorized) {

        returnYES;

    }else{

        returnNO;

    }

}

2.获取本地媒体库的音乐列表

+ (NSArray *)fetchItunsMusics {

    if (![self hasMediaLibraryAuth]) {

        return@[];

    }

    MPMediaQuery *query = [[MPMediaQuery alloc] init];

    MPMediaPropertyPredicate *albumNamePredicate = [MPMediaPropertyPredicate predicateWithValue:[NSNumber               numberWithInt:MPMediaTypeMusic] forProperty:MPMediaItemPropertyMediaType];

    [query addFilterPredicate:albumNamePredicate];

    NSArray*a = [query items];

    return a;

}

3.获取播放器实例

MPMusicPlayerApplicationController*musicPlayer = [MPMusicPlayerController applicationQueuePlayer];

4.将播放队列传给播放器

[musicPlayer setQueueWithQuery:query];

5.调用播放接口

[musicPlayer play];

6.切换歌曲

//记录下列表中的 MPMediaItem实例

MPMediaItem*mi = [self.musicItemsMap objectForKey:mid];

[musicPlayer setNowPlayingItem:mi];

[musicPlayer play];