Play local notification default sound when display

问题:

I'm writing a reminders app for iPhone that displays reminders using local notifications.

If a reminder goes off while the application is running, the local notification isn't displayed. Instead, the didReceiveLocalNotification method is called in my app delegate, and I mimic the local notification dialog by displaying a UIAlertView with the reminder text.

When local notifications are displayed outside of the app, the device vibrates and the sound specified by UILocalNotificationDefaultSoundName is played. Again, I'd like to mimic this in the app when displaying the UIAlertView.

I can vibrate the device by calling AudioServicesPlaySystemSound(kSystemSoundID_Vibrate), but I can't figure out how to play the local notification default sound. There's no equivalent SystemSoundID constant, and I'm not sure what the path would be.

tl;dr I'd like to play the local notification default sound when displaying a UIAlertView. Any ideas?

回答1:

Good question. Ideally, there would be a way of selecting a system sound using AudioServices. However, the following statement from Apple's "System Sound Services Reference" suggests otherwise:

In Mac OS X, when a user has configured System Preferences to flash the screen for alerts, or if sound cannot be rendered, calling this function will result in the screen flashing. In Mac OS X, pass the constant kSystemSoundID_UserPreferredAlert to play the alert sound selected by the user in System Preferences. In iOS there is no preferred user alert sound.

Since it seems like the SDK has little to offer, you might wish to mimick the system sounds by using your own wav file. There is a nice library at the following link, perhaps it will have the sound you're looking for: http://sites.google.com/site/iphonesounds/iPhoneOriginalSystemSounds_WAV.zip

Good luck!

回答2:

You can play the default notification sound in this way:

AudioServicesPlaySystemSound(1315);

In this link you'll find the list of the ids you can use as parameter of AudioServicesPlaySystemSound(id).

Good coding!

回答3:

Set delegate in .h file:

@interface ViewController : UIViewController <UIAlertViewDelegate>
{
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;

@end

And set method that above declared.

And in .m file do this:

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/ma.mp3", [[NSBundle mainBundle] resourcePath]]];

    NSError *error;

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Title" message:@"message" delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil]; 

    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
    audioPlayer.numberOfLoops = -1;


    [audioPlayer play];

    [alert show]; 
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
    if (buttonIndex==0) {
        [audioPlayer stop];

    }
    NSLog(@"U HAVE CLICKED BUTTON");
}

回答4:

This is addition to Andrew Little answer.

To better mimic notification sound, you also should to configure audio session:

AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryAmbient withOptions:AVAudioSessionCategoryOptionDuckOthers error:nil];

This is essential when e.g. you listen to the music and obtain notification during this.

Parameters of session above looks the same as for sound played when notification fires with application in background:

• music is silenced before and resumed after notification sound.
• device silence switch is handled correctly - sound is played only when switch is on
• volume is the same (note you may obtain different volume if you use system sound when application in background and files from Andrew Little answer)