iOS 开发笔记（一）——iOS Gesture Recognizer 手势识别

在iOS 3.2之后 UIKit中添加了 UIGestureRecognizer Class 可以用来处理手势信息

• 拍击 (任意次数的拍击)

• 向里或向外捏 (用于缩放)

• 摇动或者拖拽

• 擦碰 (以任意方向)

• 旋转 (手指朝相反方向移动)

• 长按

   实现代码：

  1、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");
  }
  
  
  2、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");
  } 
  
  3、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);
  }
  
  4、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));
  }
  
  5、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);
  }

  高级手势识别器

Simultaneous Gesture Recognizers

Custom UIGestureRecognizer

继承于UIGestureRecognizer， 在一下方法中修改：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {    
    UITouch * touch = [touches anyObject];
    self.curTickleStart = [touch locationInView:self.view];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

}

- (void)reset {

}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self reset];
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self reset];
}

 

参考资料：

1 根据 Event Handling Guide for iOS

http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/GestureRecognizers/GestureRecognizers.html

2 子龙山人的博客 IOS 5手势识别教程
http://www.cnblogs.com/andyque/archive/2011/12/30/2307060.html

3 http://www.raywenderlich.com/6567/uigesturerecognizer-tutorial-in-ios-5-pinches-pans-and-more