iOS 开发笔记（一）——iOS Gesture Recognizer 手势识别

在iOS 3.2之后 UIKit中添加了 UIGestureRecognizer Class 可以用来处理手势信息



拍击 (任意次数的拍击)

向里或向外捏 (用于缩放)

摇动或者拖拽

擦碰 (以任意方向)

旋转 (手指朝相反方向移动)

长按

实现代码：

1、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");
}

2、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");
}

3、一个手指向上、向下擦碰手势
// 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);
}

4、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));
}

5、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);
}

高级手势识别器

Simultaneous Gesture Recognizers

Custom UIGestureRecognizer

继承于UIGestureRecognizer， 在一下方法中修改：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch * touch = [touches anyObject];
self.curTickleStart = [touch locationInView:self.view];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

}

- (void)reset {

}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[self reset];
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
[self reset];
}

参考资料：
1 根据 Event Handling Guide for iOS http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/GestureRecognizers/GestureRecognizers.html 2 子龙山人的博客 IOS 5手势识别教程 http://www.cnblogs.com/andyque/archive/2011/12/30/2307060.html 3 http://www.raywenderlich.com/6567/uigesturerecognizer-tutorial-in-ios-5-pinches-pans-and-more