iPhone

iPhone – Add an UISlider For AVAudioPlayer

21 Comments

We can use AVAudioPlayer to play music. Now i want to add an UISlider as the music progress bar and user can fast skip the music.

Now i have a play button in the view and when user click it, i will play the music file as well as the following method.

  • playButtonClicked – Run when the play button is clicked
  • updateSlider – Run in 1 second interval to update the UISlider
  • sliderChange – Fast skip the music when user scroll the UISlider

Here comes the code

- (IBAction)playButtonClicked:(id)sender {
	// Read the file from resource folder and set it in the avAudioPlayer
	NSURL *fileUrl = [[NSURL alloc] initFileURLWithPath:[[NSBundle mainBundle] pathForResource:@"musicFile" ofType:@"caf"]];
	avAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileUrl error:nil];
	[avAudioPlayer setDelegate:self];
	[avAudioPlayer setVolume:1.0];

	// Set a timer which keep getting the current music time and update the UISlider in 1 sec interval
	sliderTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateSlider) userInfo:nil repeats:YES];
	// Set the maximum value of the UISlider
	aSlider.maximumValue = avAudioplayer.duration;
	// Set the valueChanged target
	[aSlider addTarget:self action:@selector(sliderChanged:) forControlEvents:UIControlEventValueChanged];

	// Play the audio
	[avAudioPlayer prepareToPlay];
	[avAudioPlayer play];
}

- (void)updateSlider {
	// Update the slider about the music time
	aSlider.value = avAudioPlayer.currentTime;
}

- (IBAction)sliderChanged:(UISlider *)sender {
	// Fast skip the music when user scroll the UISlider
	[avAudioPlayer stop];
	[avAudioPlayer setCurrentTime:aSlider.value];
	[avAudioPlayer prepareToPlay];
	[avAudioPlayer play];
}

// Stop the timer when the music is finished (Need to implement the AVAudioPlayerDelegate in the Controller header)
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag {
	// Music completed
	if (flag) {
		[sliderTimer invalidate];
	}
}

 

Please note that u have to implement the AVAudioPlayerDelegate to use the audioPlayerDidFinishPlaying method.

Done =)

Reference:

21 thoughts on “iPhone – Add an UISlider For AVAudioPlayer”

  4. Checking whether the slider is currently being dragged prevents it from jumping in updateSlider during interaction:

      if (aSlider.touchInside) {
    return;
  }

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  5. I encounter problem once i touch the slider, it cause the program terminated show main in receive SIGABRT, please help

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  7. Sorry I’m a beginner, I could not run this code on Xcode.
    Would you please upload the project files or tell me how to run the code.
    I have multiple audio files and I want to create an app that have a play button and a progress bar.

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