UIKit中包含了UIGestureRecognizer类，用于检测发生在设备中的手势。UIGestureRecognizer是一个抽象类，定义了所有手势的 基本行为，它有下面一些子类用于处理具体的手势：
1、拍击UITapGestureRecognizer (任意次数的拍击)
2、向里或向外捏UIPinchGestureRecognizer (用于缩放)
3、摇动或者拖拽UIPanGestureRecognizer
4、擦碰UISwipeGestureRecognizer (以任意方向)
5、旋转UIRotationGestureRecognizer (手指朝相反方向移动)
6、长按UILongPressGestureRecognizer对于不同类型的手势识别器，具有不同的配置属性。比如UITapGest ureRecognizer，可以配置拍击次数。界面接收到手势之后，可以发送一个消息，用于处理响应手势动作后的任务。当然，不同的手势识别器，发送的消息方法也会 有所不同。

一个手指，拍击两次手势

// 创建一个手势识别器  UITapGestureRecognizer *oneFingerTwoTaps =    [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(oneFingerTwoTaps)] autorelease];    // Set required taps and number of touches  [oneFingerTwoTaps setNumberOfTapsRequired:2];  [oneFingerTwoTaps setNumberOfTouchesRequired:1];    // Add the gesture to the view  [[self view] addGestureRecognizer:oneFingerTwoTaps];    消息方法oneFingerTwoTaps  - (void)oneFingerTwoTaps  {    NSLog(@"Action: One finger, two taps");  }

两个手指，拍击两次手势

UITapGestureRecognizer *twoFingersTwoTaps =    [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingersTwoTaps)] autorelease];  [twoFingersTwoTaps setNumberOfTapsRequired:2];  [twoFingersTwoTaps setNumberOfTouchesRequired:2];  [[self view] addGestureRecognizer:twoFingersTwoTaps];    消息方法twoFingersTwoTaps  - (void)twoFingersTwoTaps {    NSLog(@"Action: Two fingers, two taps");  } 

一个手指向上、向下擦碰手势

// 向上擦碰  UISwipeGestureRecognizer *oneFingerSwipeUp =    [[[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(oneFingerSwipeUp:)] autorelease];  [oneFingerSwipeUp setDirection:UISwipeGestureRecognizerDirectionUp];  [[self view] addGestureRecognizer:oneFingerSwipeUp];    - (void)oneFingerSwipeUp:(UISwipeGestureRecognizer *)recognizer  {    CGPoint point = [recognizer locationInView:[self view]];    NSLog(@"Swipe up - start location: %f,%f", point.x, point.y);  }    // 向下擦碰  UISwipeGestureRecognizer *oneFingerSwipeDown =    [[[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(oneFingerSwipeDown:)] autorelease];  [oneFingerSwipeDown setDirection:UISwipeGestureRecognizerDirectionDown];  [[self view] addGestureRecognizer:oneFingerSwipeDown];    - (void)oneFingerSwipeDown:(UISwipeGestureRecognizer *)recognizer  {    CGPoint point = [recognizer locationInView:[self view]];    NSLog(@"Swipe down - start location: %f,%f", point.x, point.y);  }

旋转手势

UIRotationGestureRecognizer *twoFingersRotate =    [[[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingersRotate:)] autorelease];  [[self view] addGestureRecognizer:twoFingersRotate];    - (void)twoFingersRotate:(UIRotationGestureRecognizer *)recognizer  {    // Convert the radian value to show the degree of rotation    NSLog(@"Rotation in degrees since last change: %f", [recognizer rotation] * (180 / M_PI));  }

向里或向外捏的手势

UIPinchGestureRecognizer *twoFingerPinch =    [[[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingerPinch:)] autorelease];  [[self view] addGestureRecognizer:twoFingerPinch];    - (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer  {    NSLog(@"Pinch scale: %f", recognizer.scale);  }