如何使用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、滑动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、向下滑动手势

// 向上滑动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);}// 向下滑动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);}

 

 

 

 

 

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");}