ios single AVAudioPlayer - ios

Question

I'm working on an ios app with uitabviewcontroller that plays some music. I don't want each tab viewcontroller to create it's own audio player. I want to have one single audio player and have all the viewcontrollers share it.
so I have created a class called player, which would initiate avaudioplayer with the song url and plays the song,
#import <AVFoundation/AVFoundation.h>
#interface player : NSObject {
AVAudioPlayer *theMainAudio;
}
-(void)playSong:(NSString *)songName;
#end
I want to create only one instance of this class and all my viewcontrollers share it. I've tried creating it in my delegate,
#interface AppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {
UIWindow *window;
UITabBarController *tabBarController;
player *theMainPlayer;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
#property (nonatomic, retain) player *theMainPlayer;
#end
in .m file,
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//some other stuff here....
theMainPlayer = [[player alloc]init];
return YES;
}
and then I called it in my viewcontrollers,
player myPlayer = ((AppDelegate *)[UIApplication sharedApplication].delegate).theMainPlayer;
but this didn't work.
can anyone tell me what's wrong with what I've done or if there is any other way to do what I want to do, which is to create a player object and share it among all of my viewcontrollers.
Thanks

Answer 1

create a singleton, in your player.m
#import "player.h"
#implementation player
static player *sharedInstance = nil;
+ (player *)sharedInstance {
if (sharedInstance == nil) {
sharedInstance = [[super allocWithZone:NULL] init];
}
return sharedInstance;
}
- (id)init
{
self = [super init];
if (self) {
// Work your initialising here as you normally would
}
return self;
}
-(void)playSong:(NSString *)songName
{
// do your stuff here
}
to use this class, just import the player.h
[[player sharedInstance] playSong:#"something"];

Answer 2

How did it go wrong? To me it seems the last line would cause compile error. You should add asterisk for class declaration :
player * myPlayer = ((AppDelegate *)[UIApplication sharedApplication].delegate).theMainPlayer;
Other than that, I didn't catch anything.
But I prefer using Singleton pattern for cases like this.
Reference :
http://developer.apple.com/library/mac/#documentation/General/Conceptual/DevPedia-CocoaCore/Singleton.html
http://www.galloway.me.uk/tutorials/singleton-classes/