iPhone：如何在特定时间播放声音？

Question

I have written the following code:

-(void)runTimer
{
    myTicker=[NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(showActivity) userInfo:nil repeats:YES];
    myTicker = [NSTimer scheduledTimerWithTimeInterval:60.00 target:self selector:@selector(vibrate) userInfo:nil repeats:YES];
}

-(void)showActivity
{
    NSDateFormatter *formatter =
                  [[[NSDateFormatter alloc] init] autorelease];
            NSDate *date = [NSDate date];
        [formatter setTimeStyle:NSDateFormatterMediumStyle];
         [timerLabel setText:[formatter stringFromDate:date]];
}
-(void) vibrate{
AudioServicesPlaySystemSound (kSystemSoundID_Vibrate);

}

I want to play an audio file instead of vibrating the iPhone. Is that possible?

Answer 1

Tangential to the main question but the method called by the timer selector should be of the form...

-(void) aribtaryMethodName:(NSTimer *) theTimer;

...or it may not be called properly. It's selector should look like this:

myTicker=[NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(aribtaryMethodName:) userInfo:nil repeats:YES];

Answer 2

-(IBAction)slider1Changed:(id)sender
{
    [timer invalidate];
    float sliderValue=slider1.value;
    int totalSecond=(int)sliderValue;
    time=totalSecond;
    int sec= totalSecond %60;
    int min= (totalSecond -sec)/60;
    sliderValue=(float)totalSecond;
    runTime.text=[NSString stringWithFormat:@"%d:%.2d",min,sec];
    [slider1 setValue:sliderValue];
    timer =   [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerChanged) userInfo:nil repeats:YES];

    // to play the audio from particular time duration
    [player setCurrentTime:totalSecond];
}

-(void)timerChanged
{
   int totalSecond=[player duration];

   float slider1Time=(float)time;
   if (time <= totalSecond) {
      int sec= time %60;
      int min= (time -sec)/60;
      runTime.text=[NSString stringWithFormat:@"%d:%.2d",min,sec];
      [slider1 setValue:slider1Time];
   }
   else
   {
      [player stop];
      [timer invalidate];
   }
   time +=1;

}

Answer 3

Yes. Assume you have a .caf file, you can play it with

SystemSoundID sound_id;
AudioServicesCreateSystemSoundID(NSURL_of_your_caf_file, &sound_id);
...
AudioServicesPlaySystemSound(sound_id);

To play music you may want to use AVAudioPlayer instead.

Answer 4

Sure. See AVAudioPlayer class.

Answer 5

Check Apple's sample project BubbleLevel . You want the SoundEffect.h and SoundEffect.m into your project and then just call:

mySound = [[SoundEffect alloc]
    initWithContentsOfFile:[mainBundle pathForResource:@"mySound"
    ofType:@"aif"]];
[mySound play];    

Warning: I was able to play only AIF sounds converted via iTunes. Anything else failed, including CAF files. In short: import your whatever sound into iTunes (drag'n'drop), change export to AIF format and then export the file.