使用iOS手势UIGestureRecognizer

http://www.oschina.net/code/snippet_54100_8106

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： 

[代码] 一个手指，拍击两次手势

01	// 创建一个手势识别器

02	UITapGestureRecognizer *oneFingerTwoTaps =

03	[[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(oneFingerTwoTaps)] autorelease];

04

05	// Set required taps and number of touches

06	[oneFingerTwoTaps setNumberOfTapsRequired:2];

07	[oneFingerTwoTaps setNumberOfTouchesRequired:1];

08

09	// Add the gesture to the view

10	[[self view] addGestureRecognizer:oneFingerTwoTaps];

11

12	消息方法oneFingerTwoTaps

13	- (void)oneFingerTwoTaps

14

{

15	NSLog(@"Action: One finger, two taps");

16

}

[代码] 两个手指，拍击两次手势

01	UITapGestureRecognizer *twoFingersTwoTaps =

02	[[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingersTwoTaps)] autorelease];

03	[twoFingersTwoTaps setNumberOfTapsRequired:2];

04	[twoFingersTwoTaps setNumberOfTouchesRequired:2];

05	[[self view] addGestureRecognizer:twoFingersTwoTaps];

06

07	消息方法twoFingersTwoTaps

08	- (void)twoFingersTwoTaps {

09	NSLog(@"Action: Two fingers, two taps");

10

}

[代码] 一个手指向上、向下擦碰手势

01

// 向上擦碰

02	UISwipeGestureRecognizer *oneFingerSwipeUp =

03	[[[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(oneFingerSwipeUp:)] autorelease];

04	[oneFingerSwipeUp setDirection:UISwipeGestureRecognizerDirectionUp];

05	[[self view] addGestureRecognizer:oneFingerSwipeUp];

06

07	- (void)oneFingerSwipeUp:(UISwipeGestureRecognizer *)recognizer

08

{

09	CGPoint point = [recognizer locationInView:[self view]];

10	NSLog(@"Swipe up - start location: %f,%f", point.x, point.y);

11

}

12

13

// 向下擦碰

14	UISwipeGestureRecognizer *oneFingerSwipeDown =

15	[[[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(oneFingerSwipeDown:)] autorelease];

16	[oneFingerSwipeDown setDirection:UISwipeGestureRecognizerDirectionDown];

17	[[self view] addGestureRecognizer:oneFingerSwipeDown];

18

19	- (void)oneFingerSwipeDown:(UISwipeGestureRecognizer *)recognizer

20

{

21	CGPoint point = [recognizer locationInView:[self view]];

22	NSLog(@"Swipe down - start location: %f,%f", point.x, point.y);

23

}

[代码] 旋转手势

1	UIRotationGestureRecognizer *twoFingersRotate =

2	[[[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingersRotate:)] autorelease];

3	[[self view] addGestureRecognizer:twoFingersRotate];

4

5	- (void)twoFingersRotate:(UIRotationGestureRecognizer *)recognizer

6

{

7	// Convert the radian value to show the degree of rotation

8	NSLog(@"Rotation in degrees since last change: %f", [recognizer rotation] * (180 / M_PI));

9

}

[代码] 向里或向外捏的手势

1	UIPinchGestureRecognizer *twoFingerPinch =

2	[[[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(twoFingerPinch:)] autorelease];

3	[[self view] addGestureRecognizer:twoFingerPinch];

4

5	- (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer

6

{

7	NSLog(@"Pinch scale: %f", recognizer.scale);

8

}