在app plist中增加
<key>UIBackgroundModes</key>
<array>
<string>audio</string>
<string>voip</string>
<string>location</string>
</array>
在函數- (void)applicationDidEnterBackground:(UIApplication *)application 中增加:
#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 40000
UIDevice* device = [UIDevice currentDevice];
BOOL backgroundSupported = NO;
if ([device respondsToSelector:@selector(isMultitaskingSupported)])
backgroundSupported = device.multitaskingSupported;
UIApplication* app = [UIApplication sharedApplication];
UIBackgroundTaskIdentifier bgTask = [app beginBackgroundTaskWithExpirationHandler:^{}];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Do the work associated with the task.
[self playerAudio];
});
[app endBackgroundTask:bgTask];
#endif
播放代碼：
#include <AudioToolbox/AudioToolbox.h>
#include <AVFoundation/AVFoundation.h>
-(void)playerAudio
{
AVAudioSession *audioSession;
audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];
[audioSession setActive:YES error:nil];
AVAudioPlayer *player;
NSString *path;
NSError * error;
// 設定音樂檔案路徑
path = [[NSBundle mainBundle] pathForResource:@"alarm_clock_30" ofType:@"caf"];
// 判斷是否可以通路這個檔案
if (![[NSFileManager defaultManager] fileExistsAtPath:path])
{
NSLog(@"file not exist!");
return;
}
// 設定 player
player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:&error];
[player setDelegate:self];
self.mPlayer = player;
// 調節音量 (範圍從0到1)
player.volume = 0.4f;
// 準備buffer，減少播放延時的時間
[player prepareToPlay];
// 設定播放次數，0為播放一次，負數為循環播放
[player setNumberOfLoops:10];
NSLog(@"start play!");
[player play];
[player release];
NSLog(@"start playing...");
}
當你需要播放其他歌曲的時候應該加上
// Handle Audio Remote Control events (only available under iOS 4
if ([[UIApplication sharedApplication] respondsToSelector:@selector(beginReceivingRemoteControlEvents)]){
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
}
- (void)remoteControlReceivedWithEvent:(UIEvent *)event
{
//NSLog(@"UIEventTypeRemoteControl: %d - %d", event.type, event.subtype);
if (event.subtype == UIEventSubtypeRemoteControlTogglePlayPause) {
//NSLog(@"UIEventSubtypeRemoteControlTogglePlayPause");
[self playOrStop:nil];
}
if (event.subtype == UIEventSubtypeRemoteControlPlay) {
//NSLog(@"UIEventSubtypeRemoteControlPlay");
[self playOrStop:nil];
}
if (event.subtype == UIEventSubtypeRemoteControlPause) {
//NSLog(@"UIEventSubtypeRemoteControlPause");
[self playOrStop:nil];
}
if (event.subtype == UIEventSubtypeRemoteControlStop) {
//NSLog(@"UIEventSubtypeRemoteControlStop");
[self playOrStop:nil];
}
if (event.subtype == UIEventSubtypeRemoteControlNextTrack) {
//NSLog(@"UIEventSubtypeRemoteControlNextTrack");
[self fastForward];
}
if (event.subtype == UIEventSubtypeRemoteControlPreviousTrack) {
//NSLog(@"UIEventSubtypeRemoteControlPreviousTrack");
[self rewind];
}
}
官方文檔：
http://developer.apple.com/library/ios/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html