Volume control in iPhone OS from another view controller? - iphone

Question

If I am playing a sound in one view, does anyone know if it is possible to control the volume from another, if it is can someone explain how? I can't figure it out, I have no code to show for the volume.
The sound is called from one view and the volume slider is on another. I have coded both.
The code for the sound is
#import `<AVFoundation/AVAudioPlayer.h`>
#import "LeftViewController.h"
#implementation LeftViewController
- (IBAction)buttonrm:(id)sender
{
[self dismissModalViewControllerAnimated:YES];
}
- (IBAction)playl {
[theAudio play];
}
- (IBAction)pausel {
[theAudio pause];
}
/*
// The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
// Custom initialization
}
return self;
}
*/
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
NSString *path =[[NSBundle mainBundle] pathForResource:#"The Noisettes - Never Forget You" ofType:#"mp3"];
theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
theAudio.delegate = self;
//[theAudio play];
[super viewDidLoad];
}
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationLandscapeLeft);
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[super dealloc];
}
#end
the code for the slider is
- (void)viewDidLoad {
[super viewDidLoad];
CGRect sliderRect = CGRectMake(46,124,169,0);
UISlider *VolumeL = [[UISlider alloc] initWithFrame:sliderRect];
VolumeL.minimumValue = 0;
VolumeL.maximumValue = 100;
VolumeL.continuous = YES;
UIImage *sliderctrl = [UIImage imageNamed:#"VolumeL.png"];
//UIImage *stetchLeftTrack = [[UIImage imageNamed:#"volumel12.png"]
//stretchableImageWithLeftCapWidth:5.0 topCapHeight:0.0];
[VolumeL setThumbImage:sliderctrl forState:UIControlStateNormal];
//[VolumeL setMinimumTrackImage:stetchLeftTrack forState:UIControlStateNormal];
[VolumeL addTarget:self action:#selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
VolumeL.transform = CGAffineTransformRotate(VolumeL.transform, 270.0/180*M_PI);
[self.view addSubview:VolumeL];
[VolumeL release];
}

Answer 1

Use the delegate pattern
In the second view controller create a protocol called MyProtocol for example with one method:
- (void)didUpdateVolume:(NSUInteger)volume;
Also create a delegate instance variable to hold the delegate reference
#property (nonatomic, assign) id<MyProtocol> delegate;
And don't forget to synthesize it in the implementation.
When the volume value is updated you would send the value to the delegate
[self.delegate didUpdateVolume:newValue];
Back in the first controller adopt the MyProtocol protocol, implement didUpdateVolume, and set the value in your player.

Answer 2

Try using the Notification center.
http://blog.grio.com/2009/04/broadcasting-information-how-to-use-the-iphone-notification-center.html