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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，定義了所有手勢的基本行爲，它有下面一些子類用於處理具體的手勢：

1、拍擊UITapGestureRecognizer (任意次數的拍擊)  
2、向裏或向外捏UIPinchGestureRecognizer (用於縮放)  
3、搖動或者拖拽UIPanGestureRecognizer  
4、滑動UISwipeGestureRecognizer (以任意方向)  
5、旋轉UIRotationGestureRecognizer (手指朝相反方向移動)  
6、長按UILongPressGestureRecognizer 

對於不同類型的手勢識別器，具有不同的配置屬性。比如UITapGestureRecognizer，可以配置拍擊次數。界面接收到手勢之後，可以發送一 個消息，用於處理響應手勢動作後的任務。當然，不同的手勢識別器，發送的消息方法也會有所不同。下面列舉幾個具體示例代碼：

一個手指，拍擊兩次手勢

// 創建一個手勢識別器

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 vie
[[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、向下滑動手勢

// 向上滑動

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);

}

// 向下滑動

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);
}

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”);

}