使用iOS手势UIGestureRecognizer

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UITapGestureRecognizer，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。下面列举几个具体示例代码：  

 
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); 
 
}