使用iOS手勢UIGestureRecognizer

UIKit中包含了UIGestureRecognizer類，用於檢測發生在設備中的手勢。UIGestureRecognizer是一個抽象類，定義了全部手勢的基本行爲，它有下面一些子類用於處理具體的手勢：  

　　一、拍擊UITapGestureRecognizer (任意次數的拍擊)   
　　二、向裏或向外捏UIPinchGestureRecognizer (用於縮放)   
　　三、搖動或者拖拽UIPanGestureRecognizer   
　　四、擦碰UISwipeGestureRecognizer (以任意方向)   
　　五、旋轉UIRotationGestureRecognizer (手指朝相反方向移動)   
　　六、長按UILongPressGestureRecognizer  
 
對於不一樣類型的手勢識別器，具備不一樣的配置屬性。好比UITapGestureRecognizer，能夠配置拍擊次數。界面接收到手勢以後，能夠發送一個消息，用於處理響應手勢動做後的任務。固然，不一樣的手勢識別器，發送的消息方法也會有所不一樣。下面列舉幾個具體示例代碼：  

 
一個手指，拍擊兩次手勢 
 
// 建立一個手勢識別器 
 
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"); 
 
} 
 
兩個手指，拍擊兩次手勢 
 
    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"); 
 
    } 
 
 
一個手指向上、向下擦碰手勢 
 
// 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); 
 
    } 
 
旋轉手勢 
 
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)); 
 
} 
 
向裏或向外捏的手勢 
 
UIPinchGestureRecognizer *twoFingerPinch = 
 
  [[[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingerPinch:)] autorelease]; 
 
[[self view] addGestureRecognizer:twoFingerPinch]; 
 
 
 
- (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer 
 
{ 
 
  NSLog(@"Pinch scale: %f", recognizer.scale); 
 
}