iOS开发学习之触摸事件和手势识别

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

1 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event2 {3     NSLog(@"触摸开始");4     for (UITouch *touch in touches) {5         NSLog(@"%@", touch);6     }7 }

 

#pragma mark 触摸移动

 1 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 2 { 3     NSLog(@"触摸移动Touch对象个数：%d",[touches count]); 4     // 要移动界面上黄颜色的视图 5      6     // 1. 得到当前手指的位置 7     UITouch *touch = [touches anyObject]; 8     CGPoint location = [touch locationInView:self.view]; 9     // 2. 得到上一次手指的位置10     CGPoint preLocation = [touch previousLocationInView:self.view];11     // 3. 计算两个位置之间的偏移12     CGPoint offset = CGPointMake(location.x - preLocation.x, location.y - preLocation.y);13     // 4. 使用计算出来的偏移量，调整视图的位置14     [_demoView setCenter:CGPointMake(_demoView.center.x + offset.x, _demoView.center.y + offset.y)];15     16     // 完整的UITouch事件调试方法17     NSLog(@"触摸移动");18     for (UITouch *touch in touches) {19         NSLog(@"%@", touch);20     }21 }22  23 #pragma mark 触摸结束24 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event25 {26     // 完整的UITouch事件调试方法27     NSLog(@"触摸完成");28     for (UITouch *touch in touches) {29         NSLog(@"%@", touch);30     }31 }32  33 #pragma mark 触摸中断34 - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event35 {36     // 完整的UITouch事件调试方法37     NSLog(@"触摸中断");38     for (UITouch *touch in touches) {39         NSLog(@"%@", touch);40     }41 }

 

Swift

 1 override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) { 2         println("touchesBegan") 3          4         //获取touches数量 5         let numTouches = touches.count 6          7         //获取点击屏幕的次数 8         let tapTouches = (touches as NSSet).anyObject()?.tapCount 9         10         //获取事件发生时间11         let timestamp = event.timestamp12         13         //获取当前相对于self.view的坐标14         let locationPoint = (touches as NSSet).anyObject()?.locationInView(self.view)15         16         //获取上一次相对于self.view的坐标17         let previousPoint = (touches as NSSet).anyObject()?.previousLocationInView(self.view)18         19         //允许使用手势20         self.view.userInteractionEnabled = true21         22         //支持多点触摸23         self.view.multipleTouchEnabled = true24         25         println("\(tapTouches)")26         27         28         //判断如果有两个触摸点29         if touches.count == 230         {31             //获取触摸集合32             let twoTouches = (touches as NSSet).allObjects33             34             //获取触摸数组35             let first:UITouch = twoTouches[0] as! UITouch //第1个触摸点36             let second:UITouch = twoTouches[1]as! UITouch //第2个触摸点37             38             //获取第1个点相对于self.view的坐标39             let firstPoint:CGPoint = first.locationInView(self.view)40             41             //获取第1个点相对于self.view的坐标42             let secondPoint:CGPoint = second.locationInView(self.view)43             44             //计算两点之间的距离45             let deltaX = secondPoint.x - firstPoint.x;46             let deltaY = secondPoint.y - firstPoint.y;47             let initialDistance = sqrt(deltaX*deltaX + deltaY*deltaY )48             49             println("两点间距离是：\(initialDistance)")50         }51     }52     53     //手指在移动54 //    override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {55     56     //2015年5月2后修改57     override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) {58         59         println("touchesMoved")60     }61     62     //触摸结束63 //    override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {64     65     //2015年5月2后修改66     override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {67         68         println("touchesEnded")69     }70     71     //触摸意外终止72     //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73 //    override func touchesCancelled(touches: NSSet!, withEvent event: UIEvent!) {74     75     //2015年5月2后修改76     override func touchesCancelled(touches: Set<NSObject>!, withEvent event: UIEvent!) {77         78         println("touchesCancelled")79     }80     

 

 

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

 1 - (void)viewDidLoad 2 { 3     [super viewDidLoad]; 4     5     // 根据实例化方法，我们知道： 6     // 1.有一个处理消息的对象，应该是self 7     // 2.我们需要定义一个方法，当手势识别检测到的时候，运行 8     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapAction:)]; 9     // setNumberOfTapsRequired 点按次数10     [tap setNumberOfTapsRequired:1];11     // setNumberOfTouchesRequired 点按的手指数量12     [tap setNumberOfTouchesRequired:1];13     // 把手势识别增加到视图上14     [self.demoView addGestureRecognizer:tap];15     16    17     UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchAction:)];18     [self.demoView addGestureRecognizer:pinch];19     20    21     UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(rotationAction:)];22     [self.demoView addGestureRecognizer:rotation];23     24    25     UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panAction:)];26     [self.demoView addGestureRecognizer:pan];27     28    29     UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPressAction:)];30     [self.demoView addGestureRecognizer:longPress];31     32    33     // 向左扫34     UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];35     [swipeLeft setDirection:UISwipeGestureRecognizerDirectionLeft];36     [self.view addGestureRecognizer:swipeLeft];37     // 向右扫38     UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];39     [swipeRight setDirection:UISwipeGestureRecognizerDirectionRight];40     [self.view addGestureRecognizer:swipeRight];41     // 向上扫42     UISwipeGestureRecognizer *swipeTop = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];43     [swipeTop setDirection:UISwipeGestureRecognizerDirectionUp];44     [self.view addGestureRecognizer:swipeTop];45     // 向下扫46     UISwipeGestureRecognizer *swipeDown = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeAction:)];47     [swipeDown setDirection:UISwipeGestureRecognizerDirectionDown];48     [self.view addGestureRecognizer:swipeDown];49 }50  51 - (void)didReceiveMemoryWarning52 {53     [super didReceiveMemoryWarning];54     // Dispose of any resources that can be recreated.55 }

#pragma mark - 轻扫手势

 1 - (void)swipeAction:(UISwipeGestureRecognizer *)sender 2 { 3     NSLog(@"%d", sender.direction); 4     switch (sender.direction) { 5         case UISwipeGestureRecognizerDirectionLeft: 6             NSLog(@"向左扫"); 7             break; 8         case UISwipeGestureRecognizerDirectionRight: 9             NSLog(@"向右扫");10             break;11         case UISwipeGestureRecognizerDirectionUp:12             NSLog(@"向上扫");13             break;14         case UISwipeGestureRecognizerDirectionDown:15             NSLog(@"向下扫");16             break;17         default:18             break;19     }20 }

#pragma mark - 长按手势

 1 - (void)longPressAction:(UILongPressGestureRecognizer *)sender 2 { 3     // 我们可以利用demoView的Tag属性，默认时tag=0 4     // 如果tag=0，我们放大一倍，否则，我们缩小一半 5     CGFloat scale; 6     if (_demoView.tag == 0) { 7         scale = 2.0; 8         _demoView.tag = 1; 9     } else {10         scale = 0.5;11         _demoView.tag = 0;12     }13     14     sender.view.transform = CGAffineTransformScale(sender.view.transform, scale, scale);15 }16  

 

#pragma mark - 拖放手势

 1 - (void)panAction:(UIPanGestureRecognizer *)sender 2 { 3     // 在拖放手势中是需要考虑手指的状态的UIGestureRecognizerState 4     // 在拖放手势中使用的状态是UIGestureRecognizerStateChanged 5     // 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 6     if (sender.state == UIGestureRecognizerStateChanged) { 7         // locationInView 8         [_demoView setCenter:[sender locationInView:self.view]]; 9     } else if (sender.state == UIGestureRecognizerStateEnded) {10         [_demoView setBackgroundColor:[UIColor yellowColor]];11     }12 }

#pragma mark - 旋转手势

 1 - (void)rotationAction:(UIRotationGestureRecognizer *)sender 2 { 3     sender.view.transform = CGAffineTransformRotate(sender.view.transform, sender.rotation); 4      5     // 和捏合操作类似，旋转角度同样需要方福伟 6     sender.rotation = 0.0f; 7 } 8   9 #pragma mark - 捏合手势10 - (void)pinchAction:(UIPinchGestureRecognizer *)sender11 {12     // 有关转换的内容，我们在后续动画部分再继续13     sender.view.transform = CGAffineTransformScale(sender.view.transform, sender.scale, sender.scale);14     15     // 缩放功能很简单，但是不要忘记将比例复位16     sender.scale = 1.0f;17     NSLog(@"捏我了");18 }19  20 #pragma mark - 点按手势21 - (void)tapAction:(UITapGestureRecognizer *)sender22 {23    24     NSLog(@"点我了 %@", sender);25 }26  27 #pragma mark - 手势触摸事件28 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event29 {30     NSLog(@"触摸事件！");31     // 1. 先取出UITouch对象32     // 2. 判断响应点击的UIView是不是我们需要的33     UITouch *touch = [touches anyObject];34     if ([touch view] == _imageView) {35         NSLog(@"点到图像了!");36     }37 }

Swift：

添加手势

 1         //点击事件 2         var atap = UITapGestureRecognizer(target: self, action: "tapDo:") 3         self.view.addGestureRecognizer(atap) 4         atap.numberOfTapsRequired = 1 //单击次数 5         atap.numberOfTouchesRequired = 1 //手指个数 6          7         //拖动事件 8         var aPan = UIPanGestureRecognizer(target: self, action: "handlenPan:") 9         self.view.addGestureRecognizer(aPan)10         aPan.minimumNumberOfTouches = 1 //最少手指个数11         aPan.maximumNumberOfTouches = 3 //最多手指个数12         13         //长按事件14         var aLongPress = UILongPressGestureRecognizer(target: self, action: "longPress:")15         self.view.addGestureRecognizer(aLongPress)16         aLongPress.minimumPressDuration = 1 //需要长按的时间，最小0.5s17 18         //捏合事件19         var aPinch = UIPinchGestureRecognizer(target: self, action: "pinchDo:")20         self.view.addGestureRecognizer(aPinch)21         22         //旋转事件23         var aRotation = UIRotationGestureRecognizer(target: self, action: "rotatePiece:")24         self.view.addGestureRecognizer(aRotation)25         26         //轻扫事件--左轻扫27         var leftSwipe = UISwipeGestureRecognizer(target: self, action: "leftSwipe:")28         self.view.addGestureRecognizer(leftSwipe)29         leftSwipe.direction =  UISwipeGestureRecognizerDirection.Left30         31         //轻扫事件--右轻扫32         var rightSwipe = UISwipeGestureRecognizer(target: self, action: "rightSwipe:")33         self.view.addGestureRecognizer(rightSwipe)34         rightSwipe.direction =  UISwipeGestureRecognizerDirection.Right35         36         //轻扫事件--上轻扫37         var upSwipe = UISwipeGestureRecognizer(target: self, action: "upSwipe:")38         self.view.addGestureRecognizer(upSwipe)39         upSwipe.direction =  UISwipeGestureRecognizerDirection.Up40         41         //轻扫事件--下轻扫42         var downSwipe = UISwipeGestureRecognizer(target: self, action: "downSwipe:")43         self.view.addGestureRecognizer(downSwipe)44         downSwipe.direction =  UISwipeGestureRecognizerDirection.Down45     }

实现

 1      2     //手势 3      4     //点击事件 5     func tapDo(sender:UITapGestureRecognizer) 6     { 7          8         println("点击事件") 9     }10     11     //拖动事件12     func handlenPan(sender:UIPanGestureRecognizer)13     {14         println("拖动事件")15         16         if sender.state == .Began17         {18             //拖动开始19         }20         else if sender.state == .Changed21         {22             //拖动过程23         }24         else if sender.state == .Ended25         {26             //拖动结束27         }28     }29     30     //长摁事件31     func longPress(sender:UILongPressGestureRecognizer)32     {33         println("长摁事件")34         35         36     }37     38     //捏合事件39     func pinchDo(sender:UIPinchGestureRecognizer)40     {41         println("捏合")42     }43 44     //旋转事件45     func rotatePiece(sender:UIRotationGestureRecognizer)46     {47         println("旋转")48     }49 50     51     //轻扫事件--左轻扫52     func leftSwipe(sender:UISwipeGestureRecognizer)53     {54         println("左轻扫")55     }56     57     //轻扫事件--右轻扫58     func rightSwipe(sender:UISwipeGestureRecognizer)59     {60         println("右轻扫")61     }62     63     //轻扫事件--上轻扫64     func upSwipe(sender:UISwipeGestureRecognizer)65     {66         println("上轻扫")67     }68     69     //轻扫事件--下轻扫70     func downSwipe(sender:UISwipeGestureRecognizer)71     {72         println("下轻扫")73     }

 

 

四、手机摇晃

 1 1. 新建摇晃监听视图ShakeListenerView，并且设置canBecomeFirstResponder返回YES 2 - (BOOL)canBecomeFirstResponder 3 { 4     return YES; 5 } 6 2. 在Storyboard中将ViewController的View的Class设置为：ShakeListenerView 7 3. 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 8 4. 在视图控制器中增加手势监听方法： 9 - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event10 {11     if (event.subtype == UIEventSubtypeMotionShake) {12         NSLog(@"shake phone");13     }14 }15 16 #pragma mark - 要让ViewController支持摇晃，需要写三个方法17 // 1. 成为第一响应者，视图一出现时，就应该成为第一响应者18 - (void)viewDidAppear:(BOOL)animated19 {20     [self.view becomeFirstResponder];21     // 不要忘记去实现父类方法22     [super viewDidAppear:animated];23 }24  25 // 2. 注销第一响应者，视图要关闭的时候，注销26 - (void)viewDidDisappear:(BOOL)animated27 {28     [self.view resignFirstResponder];29     // 不要忘记去实现父类方法30     [super viewDidDisappear:animated];31 }32  33 // 3. 监听并处理移动事件，判断是否摇晃了手机34 - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event35 {36     if (motion == UIEventSubtypeMotionShake) {37         NSLog(@"摇啊摇，摇到外婆桥！！！");38     }39 }