ViewControler.m

#import "ViewController.h"

@interface ViewController () {
    AVAudioRecorder *recorder;
    AVAudioPlayer *player;
}

@end

@implementation ViewController
@synthesize playButton;

- (void)viewDidLoad
{
    
    UILongPressGestureRecognizer *gesture1 = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressed:)];
    
    [gesture1 setMinimumPressDuration:1];
    [self.view addGestureRecognizer:gesture1];
    
    
    [super viewDidLoad];
	
    // Disable Stop/Play button when application launches
    [playButton setEnabled:NO];
    
    // Set the audio file
    NSArray *pathComponents = [NSArray arrayWithObjects:
                               [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject],
                               @"MyAudioMemo.m4a",
                               nil];
    NSURL *outputFileURL = [NSURL fileURLWithPathComponents:pathComponents];

    // Setup audio session
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

    // Define the recorder setting
    NSMutableDictionary *recordSetting = [[NSMutableDictionary alloc] init];
    
    [recordSetting setValue:[NSNumber numberWithInt:kAudioFormatMPEG4AAC] forKey:AVFormatIDKey];
    [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];
    [recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];
    
    // Initiate and prepare the recorder
    recorder = [[AVAudioRecorder alloc] initWithURL:outputFileURL settings:recordSetting error:nil];
    recorder.delegate = self;
    recorder.meteringEnabled = YES;
    [recorder prepareToRecord];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)longPressed:(UIGestureRecognizer *)longPress {
    if(([longPress state] == UIGestureRecognizerStateEnded) || ([longPress state] == UIGestureRecognizerStateEnded)) {
        NSLog(@"long press ended");
        [recorder stop];
        AVAudioSession *audioSession = [AVAudioSession sharedInstance];
        [audioSession setActive:NO error:nil];
    }
    else if([longPress state] == UIGestureRecognizerStateBegan) {
        NSLog(@"long press detected");
        
        if (player.playing) {
            [player stop];
        }
        
        if (!recorder.recording) {
            AVAudioSession *session = [AVAudioSession sharedInstance];
            [session setActive:YES error:nil];
            
            // Start recording
            [recorder record];
        }
    }
}


- (IBAction)playTapped:(id)sender {
    if (!recorder.recording){
        player = [[AVAudioPlayer alloc] initWithContentsOfURL:recorder.url error:nil];
        [player setDelegate:self];
        [player play];
    }
}

#pragma mark - AVAudioRecorderDelegate

- (void) audioRecorderDidFinishRecording:(AVAudioRecorder *)avrecorder successfully:(BOOL)flag{
    [playButton setEnabled:YES];
}

#pragma mark - AVAudioPlayerDelegate

- (void) audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Done"
                               message: @"Finish playing the recording!"
                              delegate: nil
                     cancelButtonTitle:@"OK"
                     otherButtonTitles:nil];
    [alert show];
}


@end