标签：des style blog class c tar
1、UIGestureRecognizer介绍
手势识别在iOS上非常重要，手势操作移动设备的重要特征，极大的增加了移动设备使用便捷性。
iOS系统在3.2以后，为方便开发这使用一些常用的手势，提供了UIGestureRecognizer类。手势识别UIGestureRecognizer类是个抽象类，下面的子类是具体的手势，开发这可以直接使用这些手势识别。
- Tap（点一下）
- Pinch（二指往內或往外拨动，平时经常用到的缩放）
- Rotation（旋转）
- Swipe（滑动，快速移动）
- Pan
（拖移，慢速移动）
- LongPress（长按）
UIGestureRecognizer的继承关系如下：
2、使用手势的步骤
使用手势很简单，分为两步：
- 创建手势实例。当创建手势时，指定一个回调方法，当手势开始，改变、或结束时，回调方法被调用。
- 添加到需要识别的View中。每个手势只对应一个View，当屏幕触摸在View的边界内时，如果手势和预定的一样，那就会回调方法。
ps：一个手势只能对应一个View，但是一个View可以有多个手势。
建议在真机上运行这些手势,模拟器操作不太方便，可能导致你认为手势失效。
3、Pan 拖动手势：
- UIImageView *snakeImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"snake.png"]];
-
snakeImageView.frame = CGRectMake(50, 50, 100, 160);
- UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc]
-
initWithTarget:self
- action:@selector(handlePan:)];
-
[snakeImageView addGestureRecognizer:panGestureRecognizer];
- [self.view setBackgroundColor:[UIColor whiteColor]];
-
[self.view addSubview:snakeImageView];
新建一个ImageView，然后添加手势
回调方法：
- - (void) handlePan:(UIPanGestureRecognizer*) recognizer
-
{
- CGPoint translation = [recognizer translationInView:self.view];
-
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
- recognizer.view.center.y + translation.y);
-
[recognizer setTranslation:CGPointZero inView:self.view];
-
-
}
4、Pinch缩放手势
- UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc]
-
initWithTarget:self
- action:@selector(handlePinch:)];<p class="p1">[<span class="s1">snakeImageView</span> <span class="s2">addGestureRecognizer</span>:pinchGestureRecognizer];</p>
- - (void) handlePinch:(UIPinchGestureRecognizer*) recognizer
-
{
- recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, recognizer.scale, recognizer.scale);
-
recognizer.scale = 1;
- }
5、Rotation旋转手势
- UIRotationGestureRecognizer *rotateRecognizer = [[UIRotationGestureRecognizer alloc]
-
initWithTarget:self
- action:@selector(handleRotate:)];
-
[snakeImageView addGestureRecognizer:rotateRecognizer];
- - (void) handleRotate:(UIRotationGestureRecognizer*) recognizer
-
{
- recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation);
-
recognizer.rotation = 0;
- }
添加了这几个手势后，运行看效果，程序中的imageView放了一个
/^\/^\
_|__| O|
\/ /~ \_/ \
\____|__________/ \
\_______
\
`\ \
\
| |
\
/ /
\
/ /
\\
/
/
\ \
/
/
\ \
/ /
_----_
\ \
/ /
_-~ ~-_
| |
( (
_-~ _--_ ~-_
_/ |
\
~-____-~ _-~ ~-_ ~-_-~
/
~-_
_-~ ~-_
_-~
~--______-~ ~-___-~
的图片，在模拟器上拖动是没问题的。缩放和旋转有点问题，估计是因为在模拟器上的模拟的两个接触点距离在imageView的边界外了，所以操作无效果。
建议在真机上运行这个手势。
在模拟器上缩放和选择的操作技巧：
可以把imageView的frame值设置大一点，按住alt键，按下触摸板(不按下不行)，这样就可以旋转和缩放了。
6、添加第二个ImagView并添加手势
记住：一个手势只能添加到一个View，两个View当然要有两个手势的实例了
- - (void)viewDidLoad
-
{
- [super viewDidLoad];
-
- UIImageView *snakeImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"snake.png"]];
-
UIImageView *dragonImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"dragon.png"]];
- snakeImageView.frame = CGRectMake(120, 120, 100, 160);
-
dragonImageView.frame = CGRectMake(50, 50, 100, 160);
- [self.view addSubview:snakeImageView];
-
[self.view addSubview:dragonImageView];
-
-
for (UIView *view in self.view.subviews) {
- UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc]
-
initWithTarget:self
- action:@selector(handlePan:)];
-
- UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc]
-
initWithTarget:self
- action:@selector(handlePinch:)];
-
- UIRotationGestureRecognizer *rotateRecognizer = [[UIRotationGestureRecognizer alloc]
-
initWithTarget:self
- action:@selector(handleRotate:)];
-
- [view addGestureRecognizer:panGestureRecognizer];
-
[view addGestureRecognizer:pinchGestureRecognizer];
- [view addGestureRecognizer:rotateRecognizer];
-
[view setUserInteractionEnabled:YES];
- }
-
[self.view setBackgroundColor:[UIColor whiteColor]];
- }
多添加了一条龙的view，两个view都能接收上面的三种手势。运行效果如下：
7、拖动(pan手势)速度(以较快的速度拖放后view有滑行的效果)
如何实现呢？
- - (void) handlePan:(UIPanGestureRecognizer*) recognizer
-
{
- CGPoint translation = [recognizer translationInView:self.view];
-
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
- recognizer.view.center.y + translation.y);
-
[recognizer setTranslation:CGPointZero inView:self.view];
-
-
if (recognizer.state == UIGestureRecognizerStateEnded) {
-
-
CGPoint velocity = [recognizer velocityInView:self.view];
- CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y));
-
CGFloat slideMult = magnitude / 200;
- NSLog(@"magnitude: %f, slideMult: %f", magnitude, slideMult);
-
- float slideFactor = 0.1 * slideMult;
-
CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor),
- recognizer.view.center.y + (velocity.y * slideFactor));
-
finalPoint.x = MIN(MAX(finalPoint.x, 0), self.view.bounds.size.width);
- finalPoint.y = MIN(MAX(finalPoint.y, 0), self.view.bounds.size.height);
-
- [UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
-
recognizer.view.center = finalPoint;
- } completion:nil];
-
- }
-
代码实现解析：
- 计算速度向量的长度（估计大部分都忘了）这些知识了。
- 如果速度向量小于200，那就会得到一个小于的小数，那么滑行会很短
- 基于速度和速度因素计算一个终点
- 确保终点不会跑出父View的边界
- 使用UIView动画使view滑动到终点
运行后，快速拖动图像view放开会看到view还会在原来的方向滑行一段路。
8、同时触发两个view的手势
手势之间是互斥的，如果你想同时触发蛇和龙的view，那么需要实现协议
UIGestureRecognizerDelegate，
- @interface ViewController : UIViewController<UIGestureRecognizerDelegate>
-
@end
并在协议这个方法里返回YES。
- -(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
-
{
- return YES;
-
}
把self作为代理设置给手势：
- panGestureRecognizer.delegate = self;
-
pinchGestureRecognizer.delegate = self;
- rotateRecognizer.delegate = self;
这样可以同时拖动或旋转缩放两个view了。
9、tap点击手势
这里为了方便看到tap的效果，当点击一下屏幕时，播放一个声音。
为了播放声音，我们加入AVFoundation.framework这个框架。
- - (AVAudioPlayer *)loadWav:(NSString *)filename {
-
NSURL * url = [[NSBundle mainBundle] URLForResource:filename withExtension:@"wav"];
- NSError * error;
-
AVAudioPlayer * player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
- if (!player) {
-
NSLog(@"Error loading %@: %@", url, error.localizedDescription);
- } else {
-
[player prepareToPlay];
- }
-
return player;
- }
我会在最后例子代码给出完整代码，添加手势的步骤和前面一样的。
- #import <UIKit/UIKit.h>
-
#import <AVFoundation/AVFoundation.h>
-
-
@interface ViewController : UIViewController<UIGestureRecognizerDelegate>
- @property (strong) AVAudioPlayer * chompPlayer;
-
@property (strong) AVAudioPlayer * hehePlayer;
-
-
@end
- - (void)handleTap:(UITapGestureRecognizer *)recognizer {
-
[self.chompPlayer play];
- }
运行，点一下某个图，就会播放一个咬东西的声音。
不过这个点击播放声音有点缺陷，就是在慢慢拖动的时候也会播放。这使得两个手势重合了。怎么解决呢？使用手势的：requireGestureRecognizerToFail方法。
10、手势的依赖性
在viewDidLoad的循环里添加这段代码：
- [tapRecognizer requireGestureRecognizerToFail:panGestureRecognizer];
意思就是，当如果pan手势失败，就是没发生拖动，才会出发tap手势。这样如果你有轻微的拖动，那就是pan手势发生了。tap的声音就不会发出来了。
11、自定义手势
自定义手势继承：UIGestureRecognizer，实现下面的方法：
- – touchesBegan:withEvent:
-
– touchesMoved:withEvent:
- – touchesEnded:withEvent:
-
- touchesCancelled:withEvent:
新建一个类，继承UIGestureRecognizer，代码如下：
.h文件
- #import <UIKit/UIKit.h>
-
typedef enum {
- DirectionUnknown = 0,
-
DirectionLeft,
- DirectionRight
-
} Direction;
-
-
@interface HappyGestureRecognizer : UIGestureRecognizer
- @property (assign) int tickleCount;
-
@property (assign) CGPoint curTickleStart;
- @property (assign) Direction lastDirection;
-
- @end
.m文件
- #import "HappyGestureRecognizer.h"
-
#import <UIKit/UIGestureRecognizerSubclass.h>
- #define REQUIRED_TICKLES 2
-
#define MOVE_AMT_PER_TICKLE 25
-
-
@implementation HappyGestureRecognizer
-
-
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
- UITouch * touch = [touches anyObject];
-
self.curTickleStart = [touch locationInView:self.view];
- }
-
- - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
-
-
-
UITouch * touch = [touches anyObject];
- CGPoint ticklePoint = [touch locationInView:self.view];
-
CGFloat moveAmt = ticklePoint.x - self.curTickleStart.x;
- Direction curDirection;
-
if (moveAmt < 0) {
- curDirection = DirectionLeft;
-
} else {
- curDirection = DirectionRight;
-
}
- if (ABS(moveAmt) < MOVE_AMT_PER_TICKLE) return;
-
-
-
if (self.lastDirection == DirectionUnknown ||
- (self.lastDirection == DirectionLeft && curDirection == DirectionRight) ||
-
(self.lastDirection == DirectionRight && curDirection == DirectionLeft)) {
-
-
- self.tickleCount++;
-
self.curTickleStart = ticklePoint;
- self.lastDirection = curDirection;
-
-
-
- if (self.state == UIGestureRecognizerStatePossible && self.tickleCount > REQUIRED_TICKLES) {
-
[self setState:UIGestureRecognizerStateEnded];
- }
-
}
-
-
}
-
-
- (void)reset {
- self.tickleCount = 0;
-
self.curTickleStart = CGPointZero;
- self.lastDirection = DirectionUnknown;
-
if (self.state == UIGestureRecognizerStatePossible) {
- [self setState:UIGestureRecognizerStateFailed];
-
}
- }
-
- - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
-
{
- [self reset];
-
}
-
-
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
- {
-
[self reset];
- }
-
- @end
调用自定义手势和上面一样，回到这样写：
- - (void)handleHappy:(HappyGestureRecognizer *)recognizer{
-
[self.hehePlayer play];
- }
手势成功后播放呵呵笑的声音。在真机上运行，按住某个view，快速左右拖动，就会发出笑的声音了。
代码解析：
先获取起始坐标：curTickleStart
通过和ticklePoint的x值对比，得出当前的放下是向左还是向右。再算出移动的x的值是否比MOVE_AMT_PER_TICKLE距离大，如果太则返回。
再判断是否有三次是不同方向的动作，如果是则手势结束，回调。
参考：http://www.raywenderlich.com/6567/uigesturerecognizer-tutorial-in-ios-5-pinches-pans-and-more
iOS手势UIGestureRecognizer识别的详细使用(拖动,缩放,旋转,点击,手势依赖,自定义手势)
(转),布布扣,bubuko.com
iOS手势UIGestureRecognizer识别的详细使用(拖动,缩放,旋转,点击,手势依赖,自定义手势)
(转)
标签：des style blog class c tar
原文地址：http://www.cnblogs.com/awesomeSai/p/3724638.html
