[英]Do i need to use mutableCopy to NSMutableArray when using MPMediaItem in iOS?
Hello everyone please guide me something. 大家好,请指导我。
I am doing custom music app with iPodMusicPlayer
. 我正在使用
iPodMusicPlayer
做自定义音乐应用程序。
Here is some of code i load songs from iPodLibrary. 这是一些我从iPodLibrary加载歌曲的代码。
MPMediaQuery *query = [MPMediaQuery playlistsQuery];
MPMediaPropertyPredicate *filter = [MPMediaPropertyPredicate predicateWithValue:self.playlistName forProperty:MPMediaPlaylistPropertyName comparisonType:MPMediaPredicateComparisonContains];
[query addFilterPredicate:filter];
**self.app.arrayFromAppDelegate = (NSMutableArray *)[query items];**
self.userMediaItemCollection = [[MPMediaItemCollection alloc] initWithItems:self.app.arrayFromAppDelegate];
[self.player setQueueWithItemCollection:self.userMediaItemCollection];
according to above code 根据上面的代码
self.app.arrayFromAppDelegate = (NSMutableArray *)[query items];
arrayFromAppDelegate is a NSMutableArray
that i declared in AppDelegate
. arrayFromAppDelegate是我在
AppDelegate
声明的NSMutableArray
。 [query items];
return NSArray
and i added to NSMutableArray
with pointer (NSMutableArray *)
返回
NSArray
,我使用指针将其添加到NSMutableArray
(NSMutableArray *)
Is that right way when i used like that? 当我那样使用时是正确的方式吗?
or should i use like self.app.arrayFromAppDelegate = [[query items] mutableCopy];
还是我应该使用如
self.app.arrayFromAppDelegate = [[query items] mutableCopy];
Which way is the best for memory and do i need to use removeAllObject
after use mutableCopy
? 哪种方式最适合内存,在使用
mutableCopy
之后是否需要使用removeAllObject
?
Please guide me. 请指导我。
sorry for my bad english. 对不起,我的英语不好。
Thanks you for your help. 感谢您的帮助。
如果您要从NSArray
到NSMutableArray
请不要使用强制复制,而是使用可变副本。
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