iOS/iPhone Gesture Recognizer (UIGestureRecognizer) - (Objective-C , iPhone)

    UIGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc]
                                              initWithTarget:self
                                              action:@selector(gestureHandleAction:)];
    [[self view] addGestureRecognizer:gestureRecognizer];

    -(void) gestureHandleAction:(UIGestureRecognizer *) sender {
  
    }

//
//  ViewController.h
//  gestureRecognizer
//
//  Created by Weerachai on 11/17/55 BE.
//  Copyright (c) 2555 Weerachai. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
{
    IBOutlet UIImageView *imgView;
}

@end

//
//  ViewController.m
//  gestureRecognizer
//
//  Created by Weerachai on 11/17/55 BE.
//  Copyright (c) 2555 Weerachai. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()
{
    BOOL tapIsActive;
}

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.
    
    tapIsActive = TRUE;
    
    UIGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc]
                                              initWithTarget:self
                                              action:@selector(gestureHandleAction:)];
    [[self view] addGestureRecognizer:gestureRecognizer];
}

-(void) gestureHandleAction:(UIGestureRecognizer *) sender {
    
    NSLog(@"Gesture Handling");
    
    if(tapIsActive == TRUE)
    {
        imgView.image = [UIImage imageNamed:@"girl1.jpg"];
        tapIsActive = FALSE;
    }
    else
    {
        imgView.image = [UIImage imageNamed:@"girl2.jpg"];
        tapIsActive = TRUE;
    }
    
}

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

- (void)dealloc {
    [imgView release];
    [super dealloc];
}
@end