如何从iPhone音乐库中获取特定年份的所有歌曲?
大家好,我希望你们能帮助我 我正在尝试收集用户iPhone音乐库中特定年份(即2002年)的所有歌曲 然后我想通过MPMusicLayerController播放这些歌曲 似乎您无法设置MPMediaPropertyPredicate以按发布日期进行筛选,我认为这是不可能的。我真的不想做的是必须获得所有跟踪发布日期的完整数组,然后迭代所有NSDate,因为我(可能错误地)认为这对于大型库来说可能非常缓慢 实现这项任务的最佳方式是什么如何从iPhone音乐库中获取特定年份的所有歌曲?,iphone,audio,ios,mpmusicplayercontroller,Iphone,Audio,Ios,Mpmusicplayercontroller,大家好,我希望你们能帮助我 我正在尝试收集用户iPhone音乐库中特定年份(即2002年)的所有歌曲 然后我想通过MPMusicLayerController播放这些歌曲 似乎您无法设置MPMediaPropertyPredicate以按发布日期进行筛选,我认为这是不可能的。我真的不想做的是必须获得所有跟踪发布日期的完整数组,然后迭代所有NSDate,因为我(可能错误地)认为这对于大型库来说可能非常缓慢 实现这项任务的最佳方式是什么 提前谢谢。这是您要找的 allMedia = [MPMedia
提前谢谢。这是您要找的
allMedia = [MPMediaQuery songsQuery];
//MPMediaPropertyPredicate *mpp1 = [MPMediaPropertyPredicate predicateWithValue:@"2" forProperty:MPMediaItemPropertyRating comparisonType:MPMediaPredicateComparisonEqualTo];
//MPMediaPropertyPredicate *mpp2 = [MPMediaPropertyPredicate predicateWithValue:@"Pop" forProperty:MPMediaItemPropertyGenre comparisonType:MPMediaPredicateComparisonContains];
//[allMedia addFilterPredicate:mpp1];
//[allMedia addFilterPredicate:mpp2];
//[myPlayer setQueueWithQuery:allMedia];
NSArray *itemsFromGenericQuery = [allMedia items];
NSMutableArray *mArray = [[NSMutableArray alloc] init];
int i = 0;
int j=0;
NSLog(@"itemCount: %d",[itemsFromGenericQuery count]);
float playsQuery = sliderPlays.value;
if(playsQuery == 20){playsQuery = 10000;}
NSLog(@"sliderRating.value %f sliderPlays.value %.1f", [sliderRating value], playsQuery);
while(i++ < 1000){
int trackNumber = arc4random() % [itemsFromGenericQuery count];
MPMediaItem *song = [itemsFromGenericQuery objectAtIndex:trackNumber];
NSString *artistName = [song valueForProperty: MPMediaItemPropertyArtist];
NSString *title = [song valueForProperty: MPMediaItemPropertyTitle];
NSString *rating = [song valueForKey:MPMediaItemPropertyRating];
double length = [[song valueForProperty:MPMediaItemPropertyPlaybackDuration] doubleValue];
NSNumber *year = [song valueForProperty:MPMediaItemPropertyYear];
if ([year intValue] >= [def intValue] <= {
if(j++ > 50){break;}
NSLog (@"tracknumber: %d j: %d artistName: %@ title: %@ length: %@ year: %@ playcount: %d",trackNumber, j, artistName, title, length, rating, [playCount intValue]);
[mArray addObject:song];
}
if(i++ > 1000)break;
}
MPMediaItemCollection *itemCol = [[MPMediaItemCollection alloc] initWithItems:mArray];
[myPlayer setQueueWithItemCollection:itemCol];
[myPlayer setShuffleMode: MPMusicShuffleModeSongs];
[myPlayer setRepeatMode: MPMusicRepeatModeNone];
allMedia=[MPMediaQuery-songsQuery];
//MPMediaPropertyPredicate*mpp1=[MPMediaPropertyPredicate predicateWithValue:@“2”for属性:MPMediaItemPropertyRating comparisonType:MPMediaPredicateComparisonEqualTo];
//MPMediaPropertyPredicate*mpp2=[MPMediaPropertyPredicate谓词WithValue:@“Pop”for属性:MPMediaItemPropertyGenre比较类型:MPMediaPredicateComparisonContains];
//[所有媒体地址过滤器预测:mpp1];
//[所有媒体地址过滤器预测:mpp2];
//[myPlayer setQueueWithQuery:allMedia];
NSArray*itemsFromGenericQuery=[allMedia items];
NSMutableArray*mArray=[[NSMutableArray alloc]init];
int i=0;
int j=0;
NSLog(@“itemCount:%d”,[itemsFromGenericQuery count]);
float playsQuery=sliderPlays.value;
如果(playsQuery==20){playsQuery=10000;}
NSLog(@“sliderRating.value%f sliderPlays.value%.1f”,[sliderRating value],playsQuery);
而(i++<1000){
int trackNumber=arc4random()%[itemsFromGenericQuery计数];
MPMediaItem*song=[itemsFromGenericQuery对象索引:trackNumber];
NSString*artistName=[song valueForProperty:MPMediaItemPropertyArtist];
NSString*title=[song valueForProperty:MPMediaItemPropertyTitle];
NSString*评级=[song valueForKey:MPMediaItemPropertyRating];
double length=[[song valueForProperty:MPMediaItemPropertyPlaybackDuration]double value];
NSNumber*year=[song valueForProperty:MPMediaItemPropertyYear];
如果([year intValue]>=[def intValue]50){break;}
NSLog(@“tracknumber:%d j:%d艺人姓名:%@title:%@length:%@year:%@playcount:%d”,tracknumber,j,艺人姓名,头衔,长度,等级,[playcount intValue]);
[mArray addObject:song];
}
如果(i++>1000)中断;
}
MPMediaItemCollection*itemCol=[[MPMediaItemCollection alloc]initWithItems:mArray];
[myPlayer setQueueWithItemCollection:itemCol];
[myPlayer setShuffleMode:MPMusicShuffleModeSongs];
[myPlayer设置RepeatMode:MPMusicRepeatModeNone];
MPMediaItemPropertyEar是否是有效的属性?当我尝试编译时,它不存在。[allMedia items]总是返回nil