UIGestureRecognizer手势

UIGestureRecognizer是一个抽象类，定义了所有手势的基本行为，它有6个子类处理具体的手势：

1.UITapGestureRecognizer （任意手指任意次数的点击）

// 点击次数

numberOfTapsRequired

// 手指个数

numberOfTouchesRequired   

 

 

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1. UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] init];  
2. [tapGestureRecognizer addTarget:self action:@selector(gestureRecognizerHandle:)];  
3. [tapGestureRecognizer setNumberOfTapsRequired:2];  
4. [tapGestureRecognizer setNumberOfTouchesRequired:2];  
5. [self.view addGestureRecognizer:tapGestureRecognizer];  
6. [tapGestureRecognizer release];  

 

2.UIPinchGestureRecognizer （两个手指捏合动作）

 

// 手指捏合，大于1表示两个手指之间的距离变大，小于1表示两个手指之间的距离变小

scale

// 手指捏合动作时的速率（加速度）

velocity

 

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1. UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] init];  
2. [pinchGestureRecognizer addTarget:self action:@selector(gestureRecognizerHandle:)];  
3. [self.view addGestureRecognizer:pinchGestureRecognizer];  
4. [pinchGestureRecognizer release];  

 

3.UIPanGestureRecognizer (摇动或者拖拽)

 

 

// 最少手指个数

minimumNumberOfTouches

// 最多手指个数

maximumNumberOfTouches

 

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1. UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] init];  
2. [panGestureRecognizer addTarget:self action:@selector(gestureRecognizerHandle:)];  
3. [panGestureRecognizer setMinimumNumberOfTouches:1];  
4. [panGestureRecognizer setMaximumNumberOfTouches:5];  
5. [self.view addGestureRecognizer:panGestureRecognizer];  
6. [panGestureRecognizer release];  

 

4.UISwipeGestureRecognizer (手指在屏幕上滑动操作手势)

 

// 滑动手指的个数

numberOfTouchesRequired

// 手指滑动的方向 （Up,Down,Left,Right）

direction

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1. UISwipeGestureRecognizer *swipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] init];  
2. [swipeGestureRecognizer addTarget:self action:@selector(gestureRecognizerHandle:)];  
3. [swipeGestureRecognizer setNumberOfTouchesRequired:2];  
4. [swipeGestureRecognizer setDirection:UISwipeGestureRecognizerDirectionRight];  
5. [self.view addGestureRecognizer:swipeGestureRecognizer];  
6. [swipeGestureRecognizer release];  

5.UIRotationGestureRecognizer (手指在屏幕上旋转操作)

 

// 旋转方向，小于0为逆时针旋转手势，大于0为顺时针手势

rotation

// 旋转速率

velocity

 

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1. UIRotationGestureRecognizer *rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] init];  
2. [rotationGestureRecognizer addTarget:self action:@selector(gestureRecognizerHandle:)];  
3. [self.view addGestureRecognizer:rotationGestureRecognizer];  
4. [rotationGestureRecognizer release];  

 

6.UILongPressGestureRecognizer (长按手势)

 

 

// Default is 0. The number of full taps required before the press for gesture to be recognized

numberOfTapsRequired

// 需要长按的手指的个数

numberOfTouchesRequired

// 需要长按的时间，最小为0.5s

minimumPressDuration

// 手指按住允许移动的距离

allowableMovement

 

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1. UILongPressGestureRecognizer *longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] init];  
2. [longPressGestureRecognizer addTarget:self action:@selector(gestureRecognizerHandle:)];  
3. [longPressGestureRecognizer setMinimumPressDuration:1.0f];  
4. [longPressGestureRecognizer setAllowableMovement:50.0];  
5. [self.view addGestureRecognizer:longPressGestureRecognizer];  
6. [longPressGestureRecognizer release];  

tap是指轻触手势。类似鼠标操作的点击。从iOS 3.2版本开始支持完善的手势api：

    tap：轻触

    long press：在一点上长按

    pinch：两个指头捏或者放的操作

    pan：手指的拖动

    swipe：手指在屏幕上很快的滑动

    rotation：手指反向操作

这为开发者编写手势识别操作，提供了很大的方便，想想之前用android写手势滑动的代码（编写android简单的手势切换视图示例），尤其感到幸福。

    先说一下轻扫（swipe）的实现，可以参考编写简单的手势示例：Tap了解手势种类。

    在viewDidLoad方法中注册了对上、下、左、右四个方向轻松的处理方法：

       

 - (void)viewDidLoad {
           
            UISwipeGestureRecognizer *recognizer;
           
            recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeFrom:)];
            [recognizer setDirection:(UISwipeGestureRecognizerDirectionRight)];
            [[self view] addGestureRecognizer:recognizer];
            [recognizer release];
           
            recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeFrom:)];
            [recognizer setDirection:(UISwipeGestureRecognizerDirectionUp)];
            [[self view] addGestureRecognizer:recognizer];
            [recognizer release];
           
            recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeFrom:)];
            [recognizer setDirection:(UISwipeGestureRecognizerDirectionDown)];
            [[self view] addGestureRecognizer:recognizer];
            [recognizer release];
           
            recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeFrom:)];
            [recognizer setDirection:(UISwipeGestureRecognizerDirectionLeft)];
            [[self view] addGestureRecognizer:recognizer];
            [recognizer release];
           
           
            [super viewDidLoad];

         

    可以看到，都是同一个方法，handleSwipeFrom。

    在该方法中，再识别具体是哪个方向的轻扫手势，比如判断是向下的轻扫：

        -(void)handleSwipeFrom:(UISwipeGestureRecognizer *)recognizer {

            NSLog(@"Swipe received.");

           

            if (recognizer.direction==UISwipeGestureRecognizerDirectionDown) {

                NSLog(@"swipe down");

    判断是向上的轻扫：

        if (recognizer.direction==UISwipeGestureRecognizerDirectionUp) {

            NSLog(@"swipe up");