AVAudioPlayer的音量与系统音量不同

Question

I use AVAudioPlayer to play sound, but sometimes the volume becomes very low, and not as same as the system volume. When I change the system volume by press the volume button, it becomes normal. How does it happen?

the code is below:

- (void)prepareAudioSession {
    AVAudioSession *session = [AVAudioSession sharedInstance];
    NSError *setCategoryError = nil;
    if (![session setCategory:AVAudioSessionCategoryPlayback
              withOptions:AVAudioSessionCategoryOptionMixWithOthers
                    error:&setCategoryError]) {
        // handle error
    }

    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    NSError *error = nil;
    BOOL result = [audioSession setActive:YES withOptions:0 error:&error];

    if (!result && error) {
        // deal with the error
    }
}

- (void)playWithAudioPath:(NSString *)path {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void) {
    NSError *error;
    NSURL *audioFileURL = [NSURL fileURLWithPath:path];
    self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:audioFileURL error:&error];

    audioPlayer.delegate = self;

    if (error == nil) {

        [self prepareAudioSession];

        [audioPlayer setCurrentTime:0];
        [audioPlayer play];
    }
    else {
        NSLog(@"%@", error.description);
    }
});}

Answer 1

You haven't called [audioPlayer setVolume: 1.0]; to set the Volume in your code.