如何在背景iphone sdk播放音樂

Question

我正在開發一個應用程序，我已經在應用程序中設置了計時器，之后我進入后台，當時間結束時，我想在后台播放音樂。但音樂不播放？

Answer 1

引用ios-sdk_background-audio 。 你會非常樂於助人。 祝好運

Answer 2

使用此定時器代碼設置定時器

UIBackgroundTaskIdentifier bgTask =0;
UIApplication  *app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
    [app endBackgroundTask:bgTask]; 
}];

 self.secondsTimer = [NSTimer 
                         scheduledTimerWithTimeInterval:1 
                         target:self 
                         selector:@selector(timerFireMethod:) 
                         userInfo:nil 
                         repeats:NO];

fire - (void) timerFireMethod:(NSTimer *) theTimer {}

在此火災方法中使用以下代碼播放媒體文件 -

NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"tujhbinjena" ofType:@"mp3"]];

[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

NSError *error;
audioPlayer = [[AVAudioPlayer alloc]
               initWithContentsOfURL:url
               error:&error];
audioPlayer.delegate=self;
audioPlayer.volume=1.0;
if (error)
{
    NSLog(@"Error in audioPlayer: %@", 
          [error localizedDescription]);
} else {
    audioPlayer.delegate = self;
    [audioPlayer prepareToPlay];
    [audioPlayer play]
}`  

[self becomeFirstResponder]; [[AVAudioSession sharedInstance] setCategory：AVAudioSessionCategoryPlayback error：nil]; [[AVAudioSession sharedInstance] setActive：YES error：nil];

- (BOOL)canBecomeFirstResponder {
    return YES;
}

在ViewDidUnload中，您需要執行以下這些操作

[[UIApplication sharedApplication] endReceivingRemoteControlEvents];
[self resignFirstResponder];

您需要按照處理AVAudioPlayerDelegate委托方法並在后台播放音頻，您需要在Info.plist中添加一個參數即“ 必需的背景模式 ”，此鍵的值為“ App播放音頻 ”。 如果有任何疑問，請告訴我。

Answer 3

對於此功能，您可以使用此方法： -

 -(void)notificationSchedue

   {

  NSCalendar *calendar = [NSCalendar autoupdatingCurrentCalendar];

// --------- remainingTime NSUserDefaults包含未來日期-------- //

   NSString *datevalueremaining= [[NSUserDefaults   standardUserDefaults]valueForKey:@"remainingTime"];


   NSDateFormatter *dateFormat = [[[NSDateFormatter alloc] init] autorelease];
   [dateFormat setDateFormat:@"dd/MM/yyyy HH:mm:ss"];

   NSDate *dateremaining=[dateFormat dateFromString:datevalueremaining];


   NSDate *pickerDate = dateremaining;
NSDateComponents *dateComponents = [calendar components:( NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit ) 
                                               fromDate:pickerDate];
NSDateComponents *timeComponents = [calendar components:( NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) 
                                                fromDate:pickerDate];

// Set up the fire time
 NSDateComponents *dateComps = [[NSDateComponents alloc] init];

  [dateComps setDay:[dateComponents day]];

  [dateComps setMonth:[dateComponents month]];

  [dateComps setYear:[dateComponents year]];
  [dateComps setHour:[timeComponents hour]];

  [dateComps setMinute:[timeComponents minute]];
[dateComps setSecond:[timeComponents second]];
   NSDate *itemDate = [calendar dateFromComponents:dateComps];
   [dateComps release];

  if (localNotif)
  { 
     [[UIApplication sharedApplication] cancelLocalNotification:localNotif];
     [localNotif release];
   }
  localNotif = [[UILocalNotification alloc] init];
  if (localNotif == nil)
    return;

  localNotif.fireDate = itemDate;

  localNotif.timeZone = [NSTimeZone defaultTimeZone];


  localNotif.alertBody = @"Your Time is Over";

  localNotif.alertAction = @"View";



 NSString *stringvalue=[[NSUserDefaults standardUserDefaults]valueForKey:@"goodNight"];

// -----音樂應該小於或等於30秒--- //

   localNotif.soundName=@"s1.mp3";

    NSDictionary *infoDict = [NSDictionary dictionaryWithObject:@"someValue" forKey:@"someKey"];

 localNotif.userInfo = infoDict;

 [[UIApplication sharedApplication] scheduleLocalNotification:localNotif];

 }