感谢大家关注，自己找到问题的原因了。

虚拟器不支持按下"Home"后继续播放，真机Ok！

在按下设备的 “home”键后，程序在后台运行，希望继续播放乐曲。

各位老大帮看看我哪里做错了？

或缺少什么代码？谢谢。

我已经进行了如下设置：

在程序启动时

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 

// Override point for customization after application launch.

//后台运行音乐的尝试

UIDevice* device = [UIDevice currentDevice];

BOOL backgroundSupported = NO;

if ([device respondsToSelector:@selector(isMultitaskingSupported)])

backgroundSupported = device.multitaskingSupported;

NSLog(@\"backgroundSupported[%@]\",backgroundSupported ? @\"YES\" : @\"NO\");

[[AVAudioSession sharedInstance] setDelegate:self];

NSError *audioSessionError = nil;

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&audioSessionError];

if (audioSessionError)

NSLog(@\"Error setting audio category: %@\", [audioSessionError localizedDescription]);

[[AVAudioSession sharedInstance] setActive:YES error:&audioSessionError];

if (audioSessionError)

NSLog(@\"Error setting audio active: %@\", [audioSessionError localizedDescription]);

按下home键的代码

- (void) applicationDidEnterBackground:(UIApplication *)application

{

//后台运行的尝试

UIApplication *app = [UIApplication sharedApplication];

bgTask = [app beginBackgroundTaskWithExpirationHandler:^{

[app endBackgroundTask:bgTask];

bgTask = UIBackgroundTaskInvalid;

}];

// Start the long-running task and return immediately.

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

// Do the work associated with the task.

[app endBackgroundTask:bgTask];

bgTask = UIBackgroundTaskInvalid;

});

}

Info.plist局部内容：

<key>UIBackgroundModes</key>

<array>

<string>audio</string>

</array>

播放乐曲调用：

NSError *_err;

AVAudioPlayer *_player;

NSString *file = [[NSString alloc ] initWithFormat:@\"/Users/hanmj/Hanmjmusic/halo.mp3\"];

_player = [ [AVAudioPlayer alloc] initWithContentsOfURL:

[NSURL fileURLWithPath:file ] error:&_err ];

[file release];

_player.volume = 1;

[_player play];

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