iphone - 如何在 iPhone 中播放 iTunes 库中的歌曲

Question

嗨，我需要播放 iTunes 库中的一首歌曲。我已经阅读了 Apple 的 ipod 库访问指南并获得了代码。

MPMediaQuery *everything = [[MPMediaQuery alloc] init];
NSLog(@"Logging items from a generic query...");
NSArray *itemsFromGenericQuery = [everything items];
MPMediaItem *song;
for (song in itemsFromGenericQuery) 
{
    NSString *songTitle = [song valueForProperty: MPMediaItemPropertyTitle];
    NSLog (@"%@", songTitle);
}

//assign a playback queue containing all media items on the device
[myPlayer setQueueWithQuery:everything];//setQueueWithQuery:everything];

//start playing from the begining
[myPlayer play];

但是这将从库列表的最开头开始播放。当我从列表中选择歌曲时，我需要播放它。谁能帮帮我吗...

谢谢，士斌。

Answer 1

使用 MPMediaPickerController 实例，您可以从 iPod 库的歌曲列表、专辑列表等中进行选择。以下示例从 iPod 中选择所有歌曲并显示在模态视图 Controller 中。

- (IBAction) selectSong: (id) sender 
{   
    MPMediaPickerController *picker =
    [[MPMediaPickerController alloc] initWithMediaTypes: MPMediaTypeMusic];

    picker.delegate                     = self;
    picker.allowsPickingMultipleItems   = NO;
    picker.prompt                       = NSLocalizedString (@"Select any song from the list", @"Prompt to user to choose some songs to play");

    [self presentModalViewController: picker animated: YES];
    [picker release]; 
}

现在您需要实现委托(delegate)以将歌曲存储到本地变量中。这里，selectedSongCollection 是 MPMediaItemCollection 的实例。

- (void) mediaPicker: (MPMediaPickerController *) mediaPicker didPickMediaItems: (MPMediaItemCollection *) mediaItemCollection 
{
    [self dismissModalViewControllerAnimated: YES];
    selectedSongCollection=mediaItemCollection; 
}

完成选择歌曲后，实现委托(delegate)以关闭选择器:

- (void) mediaPickerDidCancel: (MPMediaPickerController *) mediaPicker 
{   
    [self dismissModalViewControllerAnimated: YES]; 
}