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 *)event2.一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 *)event3.一根或者多根手指离开屏幕- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event4.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1，24.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！！！"); } }
