iPhone开发之手势识别
总共有六种手势识别：轻击手势（TapGestureRecognizer）,轻扫手势 （SwipeGestureRecognizer）, 长按手势（LongPressGestureRecognizer）, 拖动手势（PanGestureRecognizer）, 捏合手势（PinchGestureRecognizer）,旋转手势（RotationGestureRecognizer）;
其实这些手势用touche事件完全可以实现，苹果就是把常用的触摸事件封装成手势，来提供给用户。读者完全可以用TouchesMoved来写拖动手势等。
一，用storyboard给控件添加手势识别
1.用storyboard添加手势识别，和添加一个Button的步骤一样，首先我们得找到相应的手势，把手势识别的控件拖到我们要添加手势的控件中，截图如下：
2.给我们拖出的手势添加回调事件，和给Button回调事件没啥区别的，在回调方法中添加要实现的业务逻辑即可，截图如下：
二，纯代码添加手势识别
用storyboard可以大大简化我们的操作，不过纯代码的方式还是要会的，就像要Dreamwear编辑网页一样（当然啦，storyboard的拖拽功能要比Dreamwear的拖拽强大的多），用纯代码敲出来的更为灵活，更加便 于维护。不过用storyboard可以减少我们的工作量，这两个要配合着使用才能大大的提高我们的开发效率。个人感觉用storyboard把框架搭起 来（Controller间的关系），一下小的东西还是用纯代码敲出来更好一些。下面就给出如何给我们的控件用纯代码的方式来添加手势识别。
1.轻击手势（TapGestureRecognizer）的添加
初始化代码TapGestureRecongnizer的代码如下：
//新建tap手势
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGesture:)];
//设置点击次数和点击手指数
tapGesture.numberOfTapsRequired = 1; //点击次数
tapGesture.numberOfTouchesRequired = 1; //点击手指数
[self.view addGestureRecognizer:tapGesture];
在回调方法中添加相应的业务逻辑：
//轻击手势触发方法
-(void)tapGesture:(id)sender
{
//轻击后要做的事情
}
2.长按手势（LongPressGestureRecognizer）
初始化代码：
//添加长摁手势
UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGesture:)];
//设置长按时间
longPressGesture.minimumPressDuration = 0.5; //(2秒)
[self.view addGestureRecognizer:longPressGesture];
在对应的回调方法中添加相应的方法（当手势开始时执行）：
//常摁手势触发方法
-(void)longPressGesture:(id)sender
{
UILongPressGestureRecognizer *longPress = sender;
if (longPress.state == UIGestureRecognizerStateBegan)
{
UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"提示" message:@"长按触发" delegate:nil cancelButtonTitle:@"取消" otherButtonTitles: nil];
[alter show];
}
}
代码说明：手势的常用状态如下：
-
开始：UIGestureRecognizerStateBegan
-
改变：UIGestureRecognizerStateChanged
-
结束：UIGestureRecognizerStateEnded
-
取消：UIGestureRecognizerStateCancelled
-
失败：UIGestureRecognizerStateFailed
3.轻扫手势（SwipeGestureRecognizer）
在初始化轻扫手势的时候得指定轻扫的方向，上下左右。 如果要要添加多个轻扫方向，就得添加多个轻扫手势，不过回调的是同一个方法。
添加轻扫手势，一个向左一个向右，代码如下：
//添加轻扫手势
UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
//设置轻扫的方向
swipeGesture.direction = UISwipeGestureRecognizerDirectionRight; //默认向右
[self.view addGestureRecognizer:swipeGesture];
//添加轻扫手势
UISwipeGestureRecognizer *swipeGestureLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
//设置轻扫的方向
swipeGestureLeft.direction = UISwipeGestureRecognizerDirectionLeft; //默认向右
[self.view addGestureRecognizer:swipeGestureLeft];
回调方法如下：
//轻扫手势触发方法
-(void)swipeGesture:(id)sender
{
UISwipeGestureRecognizer *swipe = sender;
if (swipe.direction == UISwipeGestureRecognizerDirectionLeft)
{
//向左轻扫做的事情
}
if (swipe.direction == UISwipeGestureRecognizerDirectionRight)
{
//向右轻扫做的事情
}
}
4.捏合手势（PinchGestureRecognizer）
捏合手势初始化
//添加捏合手势
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchGesture:)];
[self.view addGestureRecognizer:pinchGesture];
捏合手势要触发的方法（放大或者缩小图片）：
////捏合手势触发方法
-(void) pinchGesture:(id)sender
{
UIPinchGestureRecognizer *gesture = sender;
//手势改变时
if (gesture.state == UIGestureRecognizerStateChanged)
{
//捏合手势中scale属性记录的缩放比例
_imageView.transform = CGAffineTransformMakeScale(gesture.scale, gesture.scale);
}
//结束后恢复
if(gesture.state==UIGestureRecognizerStateEnded)
{
[UIView animateWithDuration:0.5 animations:^{
_imageView.transform = CGAffineTransformIdentity;//取消一切形变
}];
}
}
5.拖动手势（PanGestureRecognizer）
拖动手势的初始化
//添加拖动手势
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];
[self.view addGestureRecognizer:panGesture];
拖动手势要做的方法（通过translationInView获取移动的点，和TouchesMoved方法类似）
//拖动手势
-(void) panGesture:(id)sender
{
UIPanGestureRecognizer *panGesture = sender;
CGPoint movePoint = [panGesture translationInView:self.view];
//做你想做的事儿
}
6.旋转手势（RotationGestureRecognizer）
旋转手势的初始化
//添加旋转手势
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGesture:)];
[self.view addGestureRecognizer:rotationGesture];
旋转手势调用的方法：
//旋转手势
-(void)rotationGesture:(id)sender
{
UIRotationGestureRecognizer *gesture = sender;
if (gesture.state==UIGestureRecognizerStateChanged)
{
_imageView.transform=CGAffineTransformMakeRotation(gesture.rotation);
}
if(gesture.state==UIGestureRecognizerStateEnded)
{
[UIView animateWithDuration:1 animations:^{
_imageView.transform=CGAffineTransformIdentity;//取消形变
}];
}
}
补充：
使用手势识别
六种手势识别（继承于UIGestureRecongnizer基类）：
UITapGestureRecongnizer--检测view上的单击操作
UIPinchGestureRecongnizer--检测view上两个手指的缩放操作
UIPanGestureRecongnizer--检测view的拖拽操作
UISwipeGestureRecongnizer--检测view的轻划操作
UIRotationGestureRecongnizer--检测view的旋转操作
UILongPressGestureRecongnizer-检测view上的长按操作
UITapGestureRecongnizer 检测view上的单击操作
新建Empty Application项目，在xib中添加ImageView控件，Mode为Aspect Fit,选中User Interaction Enabled和Multiple Touch
HomeViewController.h
#import <UIKit/UIKit.h>
@interface HomeViewController : UIViewController
@property (retain, nonatomic) IBOutlet UIImageView *imageView;
@end
HomeViewController.m
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
tapGesture.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:tapGesture];
[tapGesture release];
[super viewDidLoad];
}
- (IBAction)tapGestureHandler:(UIGestureRecognizer *)sender{
if (sender.view.contentMode == UIViewContentModeScaleAspectFit) {
sender.view.contentMode = UIViewContentModeScaleAspectFill;
} else {
sender.view.contentMode = UIViewContentModeScaleAspectFit;
}
}
- (void)dealloc {
[imageView release];
[super dealloc];
}
- (void)viewDidUnload {
[self setImageView:nil];
[super viewDidUnload];
}
@end
UIPinchGestureRecongnizer 检测view上两个手指的缩放操作
HomeViewController.m
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
CGFloat lastScaleValue = 1;
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
tapGesture.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:tapGesture];
[tapGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchGestureHandler:)];
[imageView addGestureRecognizer:pinchGesture];
[pinchGesture release];
[super viewDidLoad];
}
- (IBAction)tapGestureHandler:(UIGestureRecognizer *)sender{
if (sender.view.contentMode == UIViewContentModeScaleAspectFit) {
sender.view.contentMode = UIViewContentModeScaleAspectFill;
} else {
sender.view.contentMode = UIViewContentModeScaleAspectFit;
}
}
- (IBAction)pinchGestureHandler:(UIGestureRecognizer *)sender{
CGFloat scaleValue = [(UIPinchGestureRecognizer *)sender scale];
//如果手指做放大操作，scaleValue的值大于等于1；如果手指是缩小操作，scaleValue的值小于1
if (scaleValue > 1) {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue + (scaleValue-1), lastScaleValue + (scaleValue-1));
}else {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue * scaleValue, lastScaleValue * scaleValue);
}
//用户的手指离开了屏幕，将比例值记录在 lastScaleValue 变量中
if (sender.state == UIGestureRecognizerStateEnded) {
if (scaleValue > 1) {
lastScaleValue += (scaleValue - 1);
}else {
lastScaleValue += scaleValue;
}
}
}
- (void)dealloc {
[imageView release];
[super dealloc];
}
- (void)viewDidUnload {
[self setImageView:nil];
[super viewDidUnload];
}
@end
UIRotationGestureRecongnizer 检测view的旋转操作
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
CGFloat lastScaleValue = 1;
CGFloat rotationValue;
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
tapGesture.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:tapGesture];
[tapGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchGestureHandler:)];
[imageView addGestureRecognizer:pinchGesture];
[pinchGesture release];
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGestureHandler:)];
[imageView addGestureRecognizer:rotationGesture];
[rotationGesture release];
[super viewDidLoad];
}
- (IBAction)tapGestureHandler:(UIGestureRecognizer *)sender{
if (sender.view.contentMode == UIViewContentModeScaleAspectFit) {
sender.view.contentMode = UIViewContentModeScaleAspectFill;
} else {
sender.view.contentMode = UIViewContentModeScaleAspectFit;
}
}
- (IBAction)pinchGestureHandler:(UIGestureRecognizer *)sender{
CGFloat scaleValue = [(UIPinchGestureRecognizer *)sender scale];
if (scaleValue > 1) {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue + (scaleValue-1), lastScaleValue + (scaleValue-1));
}else {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue * scaleValue, lastScaleValue * scaleValue);
}
if (sender.state == UIGestureRecognizerStateEnded) {
if (scaleValue > 1) {
lastScaleValue += (scaleValue - 1);
}else {
lastScaleValue += scaleValue;
}
}
}
- (IBAction)rotationGestureHandler:(UIGestureRecognizer *)sender{
CGFloat rotation = [(UIRotationGestureRecognizer *)sender rotation];
CGAffineTransform transform = CGAffineTransformMakeRotation(rotation + rotationValue);
sender.view.transform = transform;
if (sender.state == UIGestureRecognizerStateEnded) {
rotationValue += rotation;
}
}
- (void)dealloc {
[imageView release];
[super dealloc];
}
- (void)viewDidUnload {
[self setImageView:nil];
[super viewDidUnload];
}
@end
UIPanGestureRecongnizer 检测view的拖拽操作
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
CGFloat lastScaleValue = 1;
CGFloat rotationValue;
CGPoint positionValue;
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
tapGesture.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:tapGesture];
[tapGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchGestureHandler:)];
[imageView addGestureRecognizer:pinchGesture];
[pinchGesture release];
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGestureHandler:)];
[imageView addGestureRecognizer:rotationGesture];
[rotationGesture release];
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureHandler:)];
[imageView addGestureRecognizer:panGesture];
[panGesture release];
[super viewDidLoad];
}
- (IBAction)tapGestureHandler:(UIGestureRecognizer *)sender{
if (sender.view.contentMode == UIViewContentModeScaleAspectFit) {
sender.view.contentMode = UIViewContentModeScaleAspectFill;
} else {
sender.view.contentMode = UIViewContentModeScaleAspectFit;
}
}
- (IBAction)pinchGestureHandler:(UIGestureRecognizer *)sender{
CGFloat scaleValue = [(UIPinchGestureRecognizer *)sender scale];
if (scaleValue > 1) {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue + (scaleValue-1), lastScaleValue + (scaleValue-1));
}else {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue * scaleValue, lastScaleValue * scaleValue);
}
if (sender.state == UIGestureRecognizerStateEnded) {
if (scaleValue > 1) {
lastScaleValue += (scaleValue - 1);
}else {
lastScaleValue += scaleValue;
}
}
}
- (IBAction)rotationGestureHandler:(UIGestureRecognizer *)sender{
CGFloat rotation = [(UIRotationGestureRecognizer *)sender rotation];
CGAffineTransform transform = CGAffineTransformMakeRotation(rotation + rotationValue);
sender.view.transform = transform;
if (sender.state == UIGestureRecognizerStateEnded) {
rotationValue += rotation;
}
}
- (IBAction)panGestureHandler:(UIGestureRecognizer *)sender{
CGPoint position = [(UIPanGestureRecognizer *)sender translationInView:imageView];
sender.view.transform = CGAffineTransformMakeTranslation(position.x + position.x,
position.y + position.y);
if (sender.state == UIGestureRecognizerStateEnded) {
positionValue.x += position.x;
positionValue.y += position.y;
}
}
- (void)dealloc {
[imageView release];
[super dealloc];
}
- (void)viewDidUnload {
[self setImageView:nil];
[super viewDidUnload];
}
@end
UISwipeGestureRecongnizer 检测view的轻划操作
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
CGFloat lastScaleValue = 1;
CGFloat rotationValue;
CGPoint positionValue;
NSArray *images;
int imageIndex = 0;
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
tapGesture.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:tapGesture];
[tapGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchGestureHandler:)];
[imageView addGestureRecognizer:pinchGesture];
[pinchGesture release];
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGestureHandler:)];
[imageView addGestureRecognizer:rotationGesture];
[rotationGesture release];
/*注释panGesture的拖拽操作，否则划动和拖拽操作会产生混淆
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureHandler:)];
[imageView addGestureRecognizer:panGesture];
[panGesture release];
*/
images = [[NSArray alloc] initWithObjects:@"iphone.png", @"mm.jpg", @"avatar.png", nil];
//默认情况下是向右的手势划动
UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGestureHandler:)];
[imageView addGestureRecognizer:swipeGesture];
[swipeGesture release];
//定义向左的手势划动
UISwipeGestureRecognizer *swipeLeftGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGestureHandler:)];
swipeLeftGesture.direction = UISwipeGestureRecognizerDirectionLeft;
[imageView addGestureRecognizer:swipeLeftGesture];
[swipeLeftGesture release];
[super viewDidLoad];
}
- (IBAction)tapGestureHandler:(UIGestureRecognizer *)sender{
if (sender.view.contentMode == UIViewContentModeScaleAspectFit) {
sender.view.contentMode = UIViewContentModeScaleAspectFill;
} else {
sender.view.contentMode = UIViewContentModeScaleAspectFit;
}
}
- (IBAction)pinchGestureHandler:(UIGestureRecognizer *)sender{
CGFloat scaleValue = [(UIPinchGestureRecognizer *)sender scale];
if (scaleValue > 1) {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue + (scaleValue-1), lastScaleValue + (scaleValue-1));
}else {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue * scaleValue, lastScaleValue * scaleValue);
}
if (sender.state == UIGestureRecognizerStateEnded) {
if (scaleValue > 1) {
lastScaleValue += (scaleValue - 1);
}else {
lastScaleValue += scaleValue;
}
}
}
- (IBAction)rotationGestureHandler:(UIGestureRecognizer *)sender{
CGFloat rotation = [(UIRotationGestureRecognizer *)sender rotation];
CGAffineTransform transform = CGAffineTransformMakeRotation(rotation + rotationValue);
sender.view.transform = transform;
if (sender.state == UIGestureRecognizerStateEnded) {
rotationValue += rotation;
}
}
- (IBAction)panGestureHandler:(UIGestureRecognizer *)sender{
CGPoint position = [(UIPanGestureRecognizer *)sender translationInView:imageView];
sender.view.transform = CGAffineTransformMakeTranslation(position.x + position.x,
position.y + position.y);
if (sender.state == UIGestureRecognizerStateEnded) {
positionValue.x += position.x;
positionValue.y += position.y;
}
}
- (IBAction)swipeGestureHandler:(UIGestureRecognizer *)sender{
UISwipeGestureRecognizerDirection direction =[(UISwipeGestureRecognizer *)sender direction];
switch (direction) {
case UISwipeGestureRecognizerDirectionUp:
NSLog(@"向上划动");
break;
case UISwipeGestureRecognizerDirectionDown:
NSLog(@"向下划动");
break;
case UISwipeGestureRecognizerDirectionLeft:
imageIndex++;
break;
case UISwipeGestureRecognizerDirectionRight:
imageIndex--;
break;
default:
break;
}
imageIndex = (imageIndex < 0) ? ([images count] - 1):imageIndex % [images count];
imageView.image = [UIImage imageNamed:[images objectAtIndex:imageIndex]];
}
- (void)dealloc {
[images release];
[imageView release];
[super dealloc];
}
- (void)viewDidUnload {
[self setImageView:nil];
[super viewDidUnload];
}
@end
UILongPressGestureRecongnizer 检测view上的长按操作
添加UIActionSheetDelegate协议
HomeViewController.h
#import <UIKit/UIKit.h>
@interface HomeViewController : UIViewController
<UIActionSheetDelegate>{}
@property (retain, nonatomic) IBOutlet UIImageView *imageView;
@end
HomeViewController.m
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
CGFloat lastScaleValue = 1;
CGFloat rotationValue;
CGPoint positionValue;
NSArray *images;
int imageIndex = 0;
- (void)viewDidLoad
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
tapGesture.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:tapGesture];
[tapGesture release];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchGestureHandler:)];
[imageView addGestureRecognizer:pinchGesture];
[pinchGesture release];
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGestureHandler:)];
[imageView addGestureRecognizer:rotationGesture];
[rotationGesture release];
/*注释panGesture的拖拽操作，否则划动和拖拽操作会产生混淆
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureHandler:)];
[imageView addGestureRecognizer:panGesture];
[panGesture release];
*/
images = [[NSArray alloc] initWithObjects:@"iphone.png", @"mm.jpg", @"avatar.png", nil];
//默认情况下是向右的手势划动
UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGestureHandler:)];
[imageView addGestureRecognizer:swipeGesture];
[swipeGesture release];
//定义向左的手势划动
UISwipeGestureRecognizer *swipeLeftGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGestureHandler:)];
swipeLeftGesture.direction = UISwipeGestureRecognizerDirectionLeft;
[imageView addGestureRecognizer:swipeLeftGesture];
[swipeLeftGesture release];
//开始长按的内容部分
UILongPressGestureRecognizer *longpressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longpressGestureHandler:)];
longpressGesture.minimumPressDuration = 1;
longpressGesture.allowableMovement = 15;
longpressGesture.numberOfTouchesRequired = 1;
[imageView addGestureRecognizer:longpressGesture];
[longpressGesture release];
[super viewDidLoad];
}
- (IBAction)tapGestureHandler:(UIGestureRecognizer *)sender{
if (sender.view.contentMode == UIViewContentModeScaleAspectFit) {
sender.view.contentMode = UIViewContentModeScaleAspectFill;
} else {
sender.view.contentMode = UIViewContentModeScaleAspectFit;
}
}
- (IBAction)pinchGestureHandler:(UIGestureRecognizer *)sender{
CGFloat scaleValue = [(UIPinchGestureRecognizer *)sender scale];
if (scaleValue > 1) {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue + (scaleValue-1), lastScaleValue + (scaleValue-1));
}else {
sender.view.transform = CGAffineTransformMakeScale(lastScaleValue * scaleValue, lastScaleValue * scaleValue);
}
if (sender.state == UIGestureRecognizerStateEnded) {
if (scaleValue > 1) {
lastScaleValue += (scaleValue - 1);
}else {
lastScaleValue += scaleValue;
}
}
}
- (IBAction)rotationGestureHandler:(UIGestureRecognizer *)sender{
CGFloat rotation = [(UIRotationGestureRecognizer *)sender rotation];
CGAffineTransform transform = CGAffineTransformMakeRotation(rotation + rotationValue);
sender.view.transform = transform;
if (sender.state == UIGestureRecognizerStateEnded) {
rotationValue += rotation;
}
}
- (IBAction)panGestureHandler:(UIGestureRecognizer *)sender{
CGPoint position = [(UIPanGestureRecognizer *)sender translationInView:imageView];
sender.view.transform = CGAffineTransformMakeTranslation(position.x + position.x,
position.y + position.y);
if (sender.state == UIGestureRecognizerStateEnded) {
positionValue.x += position.x;
positionValue.y += position.y;
}
}
- (IBAction)swipeGestureHandler:(UIGestureRecognizer *)sender{
UISwipeGestureRecognizerDirection direction =[(UISwipeGestureRecognizer *)sender direction];
switch (direction) {
case UISwipeGestureRecognizerDirectionUp:
NSLog(@"向上划动");
break;
case UISwipeGestureRecognizerDirectionDown:
NSLog(@"向下划动");
break;
case UISwipeGestureRecognizerDirectionLeft:
imageIndex++;
break;
case UISwipeGestureRecognizerDirectionRight:
imageIndex--;
break;
default:
break;
}
imageIndex = (imageIndex < 0) ? ([images count] - 1):imageIndex % [images count];
imageView.image = [UIImage imageNamed:[images objectAtIndex:imageIndex]];
}
- (IBAction)longpressGestureHandler:(UIGestureRecognizer *)sender{
if ([(UILongPressGestureRecognizer *)sender state] == UIGestureRecognizerStateBegan) {
UIActionSheet *actionSheet = [[UIActionSheet alloc]
initWithTitle:@"图片操作"
delegate:self
cancelButtonTitle:nil
destructiveButtonTitle:nil
otherButtonTitles:@"保存", @"复制", nil];
[actionSheet showInView:self.view];
[actionSheet release];
}
}
- (void)dealloc {
[images release];
[imageView release];
[super dealloc];
}
- (void)viewDidUnload {
[self setImageView:nil];
[super viewDidUnload];
}
@end
多点触摸识别
有些时候，我们只想简单地去识别用户在屏幕上的操作，而不是只针对某个特定的view，我们可以通过以下四个方法进行屏幕的触摸的识别。
touchesBegan:withEvent:当有一个或多个手指触摸屏幕时被触发。
touchesMoved:withEvent：当有一个或多个手指在屏幕上移动时被触发。
touchesEnded:withEvent:当有一个或多个手指离开屏幕时被触发。
touchesCancelled:withEvent: 当系统事件（内存溢出警告或者来电）发生时，取消触摸操作。
检测单点触摸
HomeViewController.h code:
#import <UIKit/UIKit.h>
@interface HomeViewController : UIViewController
@property (retain, nonatomic) IBOutlet UIImageView *imageView;
@end
HomeViewController.m code:
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
NSSet *allTouches = [event allTouches];
switch ([allTouches count]) {
case 1:
{
UITouch *touch = [[allTouches allObjects] objectAtIndex:0];
if ([touch tapCount] == 1 ) {
imageView.contentMode = UIViewContentModeScaleAspectFit;
}else if ([touch tapCount] == 2) {
imageView.contentMode = UIViewContentModeScaleAspectFill;
}
}
break;
default:
break;
}
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (void)dealloc {
[imageView release];
[super dealloc];
}
@end
检测多点触摸
HomeViewController.h code:
#import <UIKit/UIKit.h>
@interface HomeViewController : UIViewController
@property (retain, nonatomic) IBOutlet UIImageView *imageView;
- (CGFloat)distance:(CGPoint)fromPoint toPoint:(CGPoint)toPoint;
@end
HomeViewController.m code:
#import "HomeViewController.h"
@interface HomeViewController ()
@end
@implementation HomeViewController
@synthesize imageView;
CGFloat originalDistance;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
NSSet *allTouches = [event allTouches];
switch ([allTouches count]) {
case 1:{
UITouch *touch = [[allTouches allObjects] objectAtIndex:0];
if ([touch tapCount] == 1 ) {
imageView.contentMode = UIViewContentModeScaleAspectFit;
}else if ([touch tapCount] == 2) {
imageView.contentMode = UIViewContentModeScaleAspectFill;
}
}
break;
case 2:{
UITouch *touch1 = [[allTouches allObjects] objectAtIndex:0];
UITouch *touch2 = [[allTouches allObjects] objectAtIndex:1];
CGPoint touch1PT = [touch1 locationInView:[self view]];
CGPoint touch2PT = [touch2 locationInView:[self view]];
NSLog(@"Touch1:%.0f, %.0f", touch1PT.x, touch1PT.y);
NSLog(@"Touch2:%.0f, %.0f", touch2PT.x, touch2PT.y);
originalDistance = [self distance:touch1PT toPoint:touch2PT];
}break;
default:
break;
}
}
- (CGFloat)distance:(CGPoint)fromPoint toPoint:(CGPoint)toPoint{
float lengthX = fromPoint.x - toPoint.x;
float lengthY = fromPoint.y - toPoint.y;
return sqrt((lengthX * lengthX) + (lengthY * lengthY));
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
NSSet *allTouches = [event allTouches];
switch ([allTouches count]) {
case 1:
break;
case 2:{
UITouch *touch1 = [[allTouches allObjects] objectAtIndex:0];
UITouch *touch2 = [[allTouches allObjects] objectAtIndex:1];
CGPoint touch1PT = [touch1 locationInView:[self view]];
CGPoint touch2PT = [touch2 locationInView:[self view]];
NSLog(@"Touch1:%.0f, %.0f", touch1PT.x, touch1PT.y);
NSLog(@"Touch2:%.0f, %.0f", touch2PT.x, touch2PT.y);
CGFloat currentDistance = [self distance:touch1PT toPoint:touch2PT];
if (currentDistance > originalDistance) {
imageView.frame = CGRectMake(imageView.frame.origin.x-2,imageView.frame.origin.y-2,
imageView.frame.size.width+4, imageView.frame.size.height+4);
}else {
imageView.frame = CGRectMake(imageView.frame.origin.x+2, imageView.frame.origin.y+2,
imageView.frame.size.width-4, imageView.frame.size.height-4);
}
originalDistance = currentDistance;
}break;
default:
break;
}
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (void)dealloc {
[imageView release];
[super dealloc];
}
@end