ios开发——实用技术OC－Swift篇&触摸与手势识别

iOS开发学习之触摸事件和手势识别

 

iOS的输入事件

• 触摸事件
• 手势识别
• 手机摇晃

一、iOS的输入事件

 

触摸事件（滑动、点击）

运动事件（摇一摇、手机倾斜、行走），不需要人为参与的

远程控制事件（耳机控制手机声音）

1⃣️iOS事件对象都是UIEvent类的实例

UIEvent类对事件类型定义了enum常量：

• typedef NS_ENUM(NSInteger, UIEventType){
• UIEventTypeTouches,
• UIEventTypeMotion,
• UIEventRemoteControl,
• };

触摸事件必须是继承UIResponser的

 

二、触摸事件

1⃣️UIView，有4种处理不同的触摸事件

UIView是UIResponder的子类，可以覆盖下列4个方法处理不同的触摸事件。

1. 一根或者多根手指开始触摸屏幕

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

2.一根或者多根手指在屏幕上移动（随着手指的移动,会持续调用该方法）

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

3.一根或者多根手指离开屏幕

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

4.触摸结束前，某个系统事件(例如电话呼入)会打断触摸过程

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event

 

#pragma mark - UITouch事件

#pragma mark 触摸开始

 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
     NSLog(@"触摸开始");
     for (UITouch *touch in touches) {
         NSLog(@"%@", touch);
     }
 }

 

#pragma mark 触摸移动

 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
 {
     NSLog(@"触摸移动Touch对象个数：%d",[touches count]);
     // 要移动界面上黄颜色的视图

     // 1. 得到当前手指的位置
     UITouch *touch = [touches anyObject];
     CGPoint location = [touch locationInView:self.view];
     // 2. 得到上一次手指的位置
     CGPoint preLocation = [touch previousLocationInView:self.view];
     // 3. 计算两个位置之间的偏移
     CGPoint offset = CGPointMake(location.x - preLocation.x, location.y - preLocation.y);
     // 4. 使用计算出来的偏移量，调整视图的位置
     [_demoView setCenter:CGPointMake(_demoView.center.x + offset.x, _demoView.center.y + offset.y)];

     // 完整的UITouch事件调试方法
     NSLog(@"触摸移动");
     for (UITouch *touch in touches) {
         NSLog(@"%@", touch);
     }
 }

 #pragma mark 触摸结束
 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
 {
     // 完整的UITouch事件调试方法
     NSLog(@"触摸完成");
     for (UITouch *touch in touches) {
         NSLog(@"%@", touch);
     }
 }

 #pragma mark 触摸中断
 - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
 {
     // 完整的UITouch事件调试方法
     NSLog(@"触摸中断");
     for (UITouch *touch in touches) {
         NSLog(@"%@", touch);
     }
 }

 

Swift

 override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
         println("touchesBegan")

         //获取touches数量
         let numTouches = touches.count

         //获取点击屏幕的次数
         let tapTouches = (touches as NSSet).anyObject()?.tapCount

         //获取事件发生时间
         let timestamp = event.timestamp

         //获取当前相对于self.view的坐标
         let locationPoint = (touches as NSSet).anyObject()?.locationInView(self.view)

         //获取上一次相对于self.view的坐标
         let previousPoint = (touches as NSSet).anyObject()?.previousLocationInView(self.view)

         //允许使用手势
         self.view.userInteractionEnabled = true

         //支持多点触摸
         self.view.multipleTouchEnabled = true

         println("\(tapTouches)")

         //判断如果有两个触摸点

         {
             //获取触摸集合
             let twoTouches = (touches as NSSet).allObjects

             //获取触摸数组
             let first:UITouch = twoTouches[] as! UITouch //第1个触摸点
             let second:UITouch = twoTouches[]as! UITouch //第2个触摸点

             //获取第1个点相对于self.view的坐标
             let firstPoint:CGPoint = first.locationInView(self.view)

             //获取第1个点相对于self.view的坐标
             let secondPoint:CGPoint = second.locationInView(self.view)

             //计算两点之间的距离
             let deltaX = secondPoint.x - firstPoint.x;
             let deltaY = secondPoint.y - firstPoint.y;
             let initialDistance = sqrt(deltaX*deltaX + deltaY*deltaY )

             println("两点间距离是：\(initialDistance)")
         }
     }

     //手指在移动
 //    override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {

     //2015年5月2后修改
     override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) {

         println("touchesMoved")
     }

     //触摸结束
 //    override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {

     //2015年5月2后修改
     override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {

         println("touchesEnded")
     }

     //触摸意外终止
     //模拟器演示：鼠标拖动的同时，按键盘command+shift+h 相当于点击手机home键，退出应用，触发touchesCancelled事件，在打电话、等情况下也会触发
 //    override func touchesCancelled(touches: NSSet!, withEvent event: UIEvent!) {

     //2015年5月2后修改
     override func touchesCancelled(touches: Set<NSObject>!, withEvent event: UIEvent!) {

         println("touchesCancelled")
     }
     

 

2⃣️触摸事件的处理

如果hit-test视图无法处理事件，则通过响应者链向上传递

1.如果hit-test视图的控制器存在，就传递给控制器；如果控制器不存在，则将其传递给它的父视图

2.如果视图或它的控制器无法处理收到的事件或消息，则将其传递给该视图的父视图

3.每一个在视图继承树中的上层视图如果不能处理收到的事件或消息，则重复上面的步骤1，2

4.在视图继承树的最上层视图，如果也不能处理收到的事件或消息，则其将事件或消息传递给窗口对象进行处理

5. 如果窗口对象也不能进行处理，则其将事件或消息传递给UIApplication对象

6.如果UIApplication也不能处理该事件或消息，则将其丢弃

当用户点击屏幕时，会产生一个UITouch对象传递给UIApplication，然后由window负责查找最适合相应触摸事件的视图对象（hitTest，pointInside）

找到合适的视图之后，Touch方法由对应的视图完成，上级视图不再接管

3⃣️不接受处理事件的三种方法

不接收用户交互：userInteractionEnabled = NO;

隐藏：hidden = YES;

透明：alpha = 0~0.01

 

三、手势识别

1⃣️iOS目前支持的手势识别（6种）

UITapGestureRecognizer(点按)

UIPinchGestureRecognizer(捏合)

UIPanGestureRecognizer(拖动)

UISwipeGestureRecognizer(轻扫)

UIRotationGestureRecognizer(旋转)

UILongPressGestureRecognizer(长按)

2⃣️手势识别的使用方法（4步）

通常在视图加载的时候定义（UIGestureRecognizer是抽象类，需要实例化使用）

创建手势识别实例

设置手势识别属性，例如手指数量，方向等

将手势识别附加到指定的视图之上

编写手势触发响应方法

3⃣️手势识别的状态（7个）

   1.  // 没有触摸事件发生，所有手势识别的默认状态

    UIGestureRecognizerStatePossible,

    // 一个手势已经开始但尚未改变或者完成时

    UIGestureRecognizerStateBegan,

    // 手势状态改变

    UIGestureRecognizerStateChanged,

    // 手势完成

    UIGestureRecognizerStateEnded,

    // 手势取消，恢复至Possible状态

    UIGestureRecognizerStateCancelled, 

    // 手势失败，恢复至Possible状态

    UIGestureRecognizerStateFailed,

    // 识别到手势识别

    UIGestureRecognizerStateRecognized =UIGestureRecognizerStateEnded 

  2.手势识别的属性

• state——手势状态view——手势发生视图

常用方法

locationInView 获得手势发生对应视图所在位置

 - (void)viewDidLoad
 {
     [super viewDidLoad];

     // 根据实例化方法，我们知道：
     // 1.有一个处理消息的对象，应该是self
     // 2.我们需要定义一个方法，当手势识别检测到的时候，运行
     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapAction:)];
     // setNumberOfTapsRequired 点按次数
     [tap setNumberOfTapsRequired:];
     // setNumberOfTouchesRequired 点按的手指数量
     [tap setNumberOfTouchesRequired:];
     // 把手势识别增加到视图上
     [self.demoView addGestureRecognizer:tap];

     UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchAction:)];
     [self.demoView addGestureRecognizer:pinch];

     UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(rotationAction:)];
     [self.demoView addGestureRecognizer:rotation];

     UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panAction:)];
     [self.demoView addGestureRecognizer:pan];

     UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPressAction:)];
     [self.demoView addGestureRecognizer:longPress];

     // 向左扫
     UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];
     [swipeLeft setDirection:UISwipeGestureRecognizerDirectionLeft];
     [self.view addGestureRecognizer:swipeLeft];
     // 向右扫
     UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];
     [swipeRight setDirection:UISwipeGestureRecognizerDirectionRight];
     [self.view addGestureRecognizer:swipeRight];
     // 向上扫
     UISwipeGestureRecognizer *swipeTop = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];
     [swipeTop setDirection:UISwipeGestureRecognizerDirectionUp];
     [self.view addGestureRecognizer:swipeTop];
     // 向下扫
     UISwipeGestureRecognizer *swipeDown = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];
     [swipeDown setDirection:UISwipeGestureRecognizerDirectionDown];
     [self.view addGestureRecognizer:swipeDown];
 }

 - (void)didReceiveMemoryWarning
 {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

#pragma mark - 轻扫手势

 - (void)swipeAction:(UISwipeGestureRecognizer *)sender
 {
     NSLog(@"%d", sender.direction);
     switch (sender.direction) {
         case UISwipeGestureRecognizerDirectionLeft:
             NSLog(@"向左扫");
             break;
         case UISwipeGestureRecognizerDirectionRight:
             NSLog(@"向右扫");
             break;
         case UISwipeGestureRecognizerDirectionUp:
             NSLog(@"向上扫");
             break;
         case UISwipeGestureRecognizerDirectionDown:
             NSLog(@"向下扫");
             break;
         default:
             break;
     }
 }

#pragma mark - 长按手势

 - (void)longPressAction:(UILongPressGestureRecognizer *)sender
 {
     // 我们可以利用demoView的Tag属性，默认时tag=0
     // 如果tag=0，我们放大一倍，否则，我们缩小一半
     CGFloat scale;
     ) {
         scale = 2.0;
         _demoView.tag = ;
     } else {
         scale = 0.5;
         _demoView.tag = ;
     }

     sender.view.transform = CGAffineTransformScale(sender.view.transform, scale, scale);
 }
  

#pragma mark - 拖放手势

 - (void)panAction:(UIPanGestureRecognizer *)sender
 {
     // 在拖放手势中是需要考虑手指的状态的UIGestureRecognizerState
     // 在拖放手势中使用的状态是UIGestureRecognizerStateChanged
     // 通常在使用拖放手势的时候，当手指离开的时候，应该做一个很小的动作，提醒用户拖放完成
     if (sender.state == UIGestureRecognizerStateChanged) {
         // locationInView
         [_demoView setCenter:[sender locationInView:self.view]];
     } else if (sender.state == UIGestureRecognizerStateEnded) {
         [_demoView setBackgroundColor:[UIColor yellowColor]];
     }
 }

#pragma mark - 旋转手势

 - (void)rotationAction:(UIRotationGestureRecognizer *)sender
 {
     sender.view.transform = CGAffineTransformRotate(sender.view.transform, sender.rotation);

     // 和捏合操作类似，旋转角度同样需要方福伟
     sender.rotation = 0.0f;
 }

 #pragma mark - 捏合手势
 - (void)pinchAction:(UIPinchGestureRecognizer *)sender
 {
     // 有关转换的内容，我们在后续动画部分再继续
     sender.view.transform = CGAffineTransformScale(sender.view.transform, sender.scale, sender.scale);

     // 缩放功能很简单，但是不要忘记将比例复位
     sender.scale = 1.0f;
     NSLog(@"捏我了");
 }

 #pragma mark - 点按手势
 - (void)tapAction:(UITapGestureRecognizer *)sender
 {

     NSLog(@"点我了 %@", sender);
 }

 #pragma mark - 手势触摸事件
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
 {
     NSLog(@"触摸事件！");
     // 1. 先取出UITouch对象
     // 2. 判断响应点击的UIView是不是我们需要的
     UITouch *touch = [touches anyObject];
     if ([touch view] == _imageView) {
         NSLog(@"点到图像了!");
     }
 }

Swift：

添加手势

         //点击事件
         var atap = UITapGestureRecognizer(target: self, action: "tapDo:")
         self.view.addGestureRecognizer(atap)
         atap.numberOfTapsRequired =  //单击次数
         atap.numberOfTouchesRequired =  //手指个数

         //拖动事件
         var aPan = UIPanGestureRecognizer(target: self, action: "handlenPan:")
         self.view.addGestureRecognizer(aPan)
         aPan.minimumNumberOfTouches =  //最少手指个数
         aPan.maximumNumberOfTouches =  //最多手指个数

         //长按事件
         var aLongPress = UILongPressGestureRecognizer(target: self, action: "longPress:")
         self.view.addGestureRecognizer(aLongPress)
         aLongPress.minimumPressDuration =  //需要长按的时间，最小0.5s

         //捏合事件
         var aPinch = UIPinchGestureRecognizer(target: self, action: "pinchDo:")
         self.view.addGestureRecognizer(aPinch)

         //旋转事件
         var aRotation = UIRotationGestureRecognizer(target: self, action: "rotatePiece:")
         self.view.addGestureRecognizer(aRotation)

         //轻扫事件--左轻扫
         var leftSwipe = UISwipeGestureRecognizer(target: self, action: "leftSwipe:")
         self.view.addGestureRecognizer(leftSwipe)
         leftSwipe.direction =  UISwipeGestureRecognizerDirection.Left

         //轻扫事件--右轻扫
         var rightSwipe = UISwipeGestureRecognizer(target: self, action: "rightSwipe:")
         self.view.addGestureRecognizer(rightSwipe)
         rightSwipe.direction =  UISwipeGestureRecognizerDirection.Right

         //轻扫事件--上轻扫
         var upSwipe = UISwipeGestureRecognizer(target: self, action: "upSwipe:")
         self.view.addGestureRecognizer(upSwipe)
         upSwipe.direction =  UISwipeGestureRecognizerDirection.Up

         //轻扫事件--下轻扫
         var downSwipe = UISwipeGestureRecognizer(target: self, action: "downSwipe:")
         self.view.addGestureRecognizer(downSwipe)
         downSwipe.direction =  UISwipeGestureRecognizerDirection.Down
     }

实现

     //手势

     //点击事件
     func tapDo(sender:UITapGestureRecognizer)
     {

         println("点击事件")
     }

     //拖动事件
     func handlenPan(sender:UIPanGestureRecognizer)
     {
         println("拖动事件")

         if sender.state == .Began
         {
             //拖动开始
         }
         else if sender.state == .Changed
         {
             //拖动过程
         }
         else if sender.state == .Ended
         {
             //拖动结束
         }
     }

     //长摁事件
     func longPress(sender:UILongPressGestureRecognizer)
     {
         println("长摁事件")

     }

     //捏合事件
     func pinchDo(sender:UIPinchGestureRecognizer)
     {
         println("捏合")
     }

     //旋转事件
     func rotatePiece(sender:UIRotationGestureRecognizer)
     {
         println("旋转")
     }

     //轻扫事件--左轻扫
     func leftSwipe(sender:UISwipeGestureRecognizer)
     {
         println("左轻扫")
     }

     //轻扫事件--右轻扫
     func rightSwipe(sender:UISwipeGestureRecognizer)
     {
         println("右轻扫")
     }

     //轻扫事件--上轻扫
     func upSwipe(sender:UISwipeGestureRecognizer)
     {
         println("上轻扫")
     }

     //轻扫事件--下轻扫
     func downSwipe(sender:UISwipeGestureRecognizer)
     {
         println("下轻扫")
     }

 

四、手机摇晃

 . 新建摇晃监听视图ShakeListenerView，并且设置canBecomeFirstResponder返回YES
 - (BOOL)canBecomeFirstResponder
 {
     return YES;
 }
 . 在Storyboard中将ViewController的View的Class设置为：ShakeListenerView
 . 在ViewController.m文件中增加：viewDidAppear和viewDidDisappear在视图出现和消失时成为/撤销第一响应者身份
 . 在视图控制器中增加手势监听方法：
 - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
 {
     if (event.subtype == UIEventSubtypeMotionShake) {
         NSLog(@"shake phone");
     }
 }
  #pragma mark - 要让ViewController支持摇晃，需要写三个方法
 // 1. 成为第一响应者，视图一出现时，就应该成为第一响应者
 - (void)viewDidAppear:(BOOL)animated
 {
     [self.view becomeFirstResponder];
     // 不要忘记去实现父类方法
     [super viewDidAppear:animated];
 }

 // 2. 注销第一响应者，视图要关闭的时候，注销
 - (void)viewDidDisappear:(BOOL)animated
 {
     [self.view resignFirstResponder];
     // 不要忘记去实现父类方法
     [super viewDidDisappear:animated];
 }

 // 3. 监听并处理移动事件，判断是否摇晃了手机
 - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
 {
     if (motion == UIEventSubtypeMotionShake) {
         NSLog(@"摇啊摇，摇到外婆桥！！！");
     }
 }