從iPod庫播放歌曲

Question

我試圖播放iPod庫中的幾首歌曲。我可以使用此代碼播放一首歌曲：

MPMusicPlayerController *musicPlayer = [MPMusicPlayerController applicationMusicPlayer]; 
MPMediaPropertyPredicate *artist = [MPMediaPropertyPredicate predicateWithValue:@"Poker Face" forProperty:MPMediaItemPropertyTitle]; 

MPMediaQuery *myArtistQuery = [[MPMediaQuery alloc] init]; 
[myArtistQuery addFilterPredicate:artist]; 

[musicPlayer setQueueWithQuery:myArtistQuery]; 
[musicPlayer play]; 

它起着一個歌曲「撲克臉」，當我加入到以前的代碼

MPMediaPropertyPredicate *artist1 = [MPMediaPropertyPredicate predicateWithValue:@"Born This Way" forProperty:MPMediaItemPropertyTitle] 

[myArtistQuery addFilterPredicate:artist1]; 

它起着什麼。我有一些歌曲標題，如果它們存在，我想播放它們。

我該怎麼做？

謝謝。

Answer 1

這裏是解決方案。從播放的iPod庫兩首歌曲的藝術家

 

MPMusicPlayerController *musicPlayer = [MPMusicPlayerController applicationMusicPlayer]; 
MPMediaQuery *everything = [[MPMediaQuery alloc] init]; 

MPMediaPropertyPredicate *artist = [MPMediaPropertyPredicate predicateWithValue:@"AC/DC" forProperty:MPMediaItemPropertyArtist]; 
[everything addFilterPredicate:artist]; 
NSArray *itemsFromGenericQuery = [everything items]; 

NSMutableArray *array = [[NSMutableArray alloc] init]; 
for (MPMediaItem *song in itemsFromGenericQuery) { 
    NSString *songTitle = [song valueForProperty: MPMediaItemPropertyTitle]; 
    if ([songTitle isEqualToString:@"Highway to Hell"]) { 
     NSLog (@"%@", songTitle); 
     [array addObject:song]; 
    } 
    if ([songTitle isEqualToString:@"Thunderstruck"]) { 
     NSLog (@"%@", songTitle); 
     [array addObject:song]; 
    } 

} 

MPMediaItemCollection *collection = [[MPMediaItemCollection alloc] initWithItems:array]; 
[musicPlayer setQueueWithItemCollection:collection]; 
// NSLog(@"%@", [[MPMediaQuery songsQuery].items); 
[musicPlayer play];