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！！！");
}
}