UIImageView *snakeImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"snake.png"]]; 
snakeImageView.frame = CGRectMake(50, 50, 100, 160); 
UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] 
                        initWithTarget:self 
                        action:@selector(handlePan:)];   
[snakeImageView addGestureRecognizer:panGestureRecognizer]; 
[self.view setBackgroundColor:[UIColor whiteColor]]; 
[self.view addSubview:snakeImageView]; 

- (void) handlePan:(UIPanGestureRecognizer*) recognizer 
{ 
  CGPoint translation = [recognizer translationInView:self.view]; 
  recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, 
                  recognizer.view.center.y + translation.y); 
  [recognizer setTranslation:CGPointZero inView:self.view]; 
   
} 

UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] 
                            initWithTarget:self 
                            action:@selector(handlePinch:)];<p class="p1">[<span class="s1">snakeImageView</span> <span class="s2">addGestureRecognizer</span>:pinchGestureRecognizer];</p> 

- (void) handlePinch:(UIPinchGestureRecognizer*) recognizer 
{ 
  recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, recognizer.scale, recognizer.scale); 
  recognizer.scale = 1; 
} 

UIRotationGestureRecognizer *rotateRecognizer = [[UIRotationGestureRecognizer alloc] 
                         initWithTarget:self 
                         action:@selector(handleRotate:)]; 
[snakeImageView addGestureRecognizer:rotateRecognizer]; 

- (void) handleRotate:(UIRotationGestureRecognizer*) recognizer 
{ 
  recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation); 
  recognizer.rotation = 0; 
} 

- (void)viewDidLoad 
{ 
  [super viewDidLoad]; 
 
  UIImageView *snakeImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"snake.png"]]; 
  UIImageView *dragonImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"dragon.png"]]; 
  snakeImageView.frame = CGRectMake(120, 120, 100, 160); 
  dragonImageView.frame = CGRectMake(50, 50, 100, 160); 
  [self.view addSubview:snakeImageView]; 
  [self.view addSubview:dragonImageView]; 
   
  for (UIView *view in self.view.subviews) { 
    UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] 
                            initWithTarget:self 
                            action:@selector(handlePan:)]; 
     
    UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] 
                              initWithTarget:self 
                              action:@selector(handlePinch:)]; 
     
    UIRotationGestureRecognizer *rotateRecognizer = [[UIRotationGestureRecognizer alloc] 
                             initWithTarget:self 
                             action:@selector(handleRotate:)]; 
     
    [view addGestureRecognizer:panGestureRecognizer]; 
    [view addGestureRecognizer:pinchGestureRecognizer]; 
    [view addGestureRecognizer:rotateRecognizer]; 
    [view setUserInteractionEnabled:YES]; 
  } 
  [self.view setBackgroundColor:[UIColor whiteColor]];    
} 

- (void) handlePan:(UIPanGestureRecognizer*) recognizer 
{ 
  CGPoint translation = [recognizer translationInView:self.view]; 
  recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, 
                    recognizer.view.center.y + translation.y); 
  [recognizer setTranslation:CGPointZero inView:self.view]; 
   
  if (recognizer.state == UIGestureRecognizerStateEnded) { 
     
    CGPoint velocity = [recognizer velocityInView:self.view]; 
    CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y)); 
    CGFloat slideMult = magnitude / 200; 
    NSLog(@"magnitude: %f, slideMult: %f", magnitude, slideMult); 
     
    float slideFactor = 0.1 * slideMult; // Increase for more of a slide 
    CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor), 
                     recognizer.view.center.y + (velocity.y * slideFactor)); 
    finalPoint.x = MIN(MAX(finalPoint.x, 0), self.view.bounds.size.width); 
    finalPoint.y = MIN(MAX(finalPoint.y, 0), self.view.bounds.size.height); 
     
    [UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{ 
      recognizer.view.center = finalPoint; 
    } completion:nil]; 
     
  } 

@interface ViewController : UIViewController<UIGestureRecognizerDelegate> 
@end 

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer 
{ 
  return YES; 
} 

panGestureRecognizer.delegate = self; 
pinchGestureRecognizer.delegate = self; 
rotateRecognizer.delegate = self; 

- (AVAudioPlayer *)loadWav:(NSString *)filename { 
  NSURL * url = [[NSBundle mainBundle] URLForResource:filename withExtension:@"wav"]; 
  NSError * error; 
  AVAudioPlayer * player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error]; 
  if (!player) { 
    NSLog(@"Error loading %@: %@", url, error.localizedDescription); 
  } else { 
    [player prepareToPlay]; 
  } 
  return player; 
} 

#import <UIKit/UIKit.h> 
#import <AVFoundation/AVFoundation.h> 
 
@interface ViewController : UIViewController<UIGestureRecognizerDelegate> 
@property (strong) AVAudioPlayer * chompPlayer; 
@property (strong) AVAudioPlayer * hehePlayer; 
 
@end 
- (void)handleTap:(UITapGestureRecognizer *)recognizer { 
  [self.chompPlayer play]; 
} 

[tapRecognizer requireGestureRecognizerToFail:panGestureRecognizer]; 

– touchesBegan:withEvent: 
– touchesMoved:withEvent: 
– touchesEnded:withEvent: 
- touchesCancelled:withEvent: 

#import <UIKit/UIKit.h> 
typedef enum { 
  DirectionUnknown = 0, 
  DirectionLeft, 
  DirectionRight 
} Direction; 
 
@interface HappyGestureRecognizer : UIGestureRecognizer 
@property (assign) int tickleCount; 
@property (assign) CGPoint curTickleStart; 
@property (assign) Direction lastDirection; 
 
@end 

#import "HappyGestureRecognizer.h" 
#import <UIKit/UIGestureRecognizerSubclass.h> 
#define REQUIRED_TICKLES    2 
#define MOVE_AMT_PER_TICKLE   25 
 
@implementation HappyGestureRecognizer 
 
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { 
  UITouch * touch = [touches anyObject]; 
  self.curTickleStart = [touch locationInView:self.view]; 
} 
 
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { 
   
  // Make sure we've moved a minimum amount since curTickleStart 
  UITouch * touch = [touches anyObject]; 
  CGPoint ticklePoint = [touch locationInView:self.view]; 
  CGFloat moveAmt = ticklePoint.x - self.curTickleStart.x; 
  Direction curDirection; 
  if (moveAmt < 0) { 
    curDirection = DirectionLeft; 
  } else { 
    curDirection = DirectionRight; 
  } 
  if (ABS(moveAmt) < MOVE_AMT_PER_TICKLE) return; 
   
  // 確認(rèn)方向改變了 
  if (self.lastDirection == DirectionUnknown || 
    (self.lastDirection == DirectionLeft && curDirection == DirectionRight) || 
    (self.lastDirection == DirectionRight && curDirection == DirectionLeft)) { 
     
    // 撓癢次數(shù) 
    self.tickleCount++; 
    self.curTickleStart = ticklePoint; 
    self.lastDirection = curDirection; 
     
    // 一旦撓癢次數(shù)超過指定數(shù)，設(shè)置手勢為結(jié)束狀態(tài) 
    // 這樣回調(diào)函數(shù)會(huì)被調(diào)用。 
    if (self.state == UIGestureRecognizerStatePossible && self.tickleCount > REQUIRED_TICKLES) { 
      [self setState:UIGestureRecognizerStateEnded]; 
    } 
  } 
   
} 
 
- (void)reset { 
  self.tickleCount = 0; 
  self.curTickleStart = CGPointZero; 
  self.lastDirection = DirectionUnknown; 
  if (self.state == UIGestureRecognizerStatePossible) { 
    [self setState:UIGestureRecognizerStateFailed]; 
  } 
} 
 
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
  [self reset]; 
} 
 
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
  [self reset]; 
} 
 
@end 

- (void)handleHappy:(HappyGestureRecognizer *)recognizer{ 
  [self.hehePlayer play]; 
}