IOS开发基础（手势事件(UiGestureRecognizer)） IOS开发基础：手势事件(UiGest

【IOS开发基础（手势事件(UiGestureRecognizer)）】在介绍之前，咱们首先要知道为什么要用手势。比如我们需要添加一些触屏、滑屏事件，比如捏合图片、双击屏幕、下拉视图等等，就会用到手势
一、手势（UIGestureRecognizer）的种类其实UIGestureRecognizer这一类并不复杂,简单来说这就是一个特殊的触摸事件,UIGestureRecognizer是一个父类,而实际操作中我们要使用它的子类,、大概有以下几种:

子类名称	名称
UITapGestureRecognizer	轻拍手势
UISwipeGestureRecognizer	轻扫手势
UILongPressGestureRecognizer	长按手势
UIPanGestureRecognizer	平移手势
UIPinchGestureRecognizer	捏合（缩放）手势
UIRotationGestureRecognizer	旋转手势
UIScreenEdgePanGestureRecognizer	屏幕边缘平移
UISharkGestureRecognizer	晃动

二、创建手势手势的创建的方法大同小异

UITapGestureRecognizer(轻拍手势)

//创建手势使用initWithTarget:action:的方法创建 UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapView:)]; //设置属性 //tap 手势一共两个属性，一个是设置轻拍次数，一个是设置点击手指个数 //设置轻拍次数 tap.numberOfTapsRequired = 2; //设置手指字数 tap.numberOfTouchesRequired = 2; //别忘了添加到testView上 [self.view addGestureRecognizer:tap]; -(void)tapView:(UITapGestureRecognizer *)sender{ //设置轻拍事件改变testView的颜色 _testView.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1]; }

UISwipeGestureRecognizer (轻扫手势)

//创建手势 UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeView:)]; //设置属性，swipe也是有两种属性设置手指个数及轻扫方向 swipe.numberOfTouchesRequired = 2; //设置轻扫方向(默认是从左往右) //direction是一个枚举值有四个选项，我们可以设置从左往右，从右往左，从下往上以及从上往下 //设置轻扫方向(默认是从左往右) swipe.direction = UISwipeGestureRecognizerDirectionLeft; [self.view addGestureRecognizer:swipe]; - (void)swipeView:(UISwipeGestureRecognizer *)sender { self.view.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1]; //可在这里获取手势位置 }

UILongPressGestureRecognizer(长按手势)

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPress:)]; //属性设置 //最小长按时间 longPress.minimumPressDuration = 2; [self.view addGestureRecognizer:longPress]; -(void)longPress:(UILongPressGestureRecognizer *)sender{ //进行判断,在什么时候触发事件 if (sender.state == UIGestureRecognizerStateBegan) { NSLog(@"长按状态"); //改变testView颜色 self.view.backgroundColor = [UIColor colorWithRed:arc4random()%256/255.0 green:arc4random()%256/255.0 blue:arc4random()%256/255.0 alpha:1]; } }

UIPanGestureRecognizer(拖拽手势)

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)]; [self.imageV addGestureRecognizer:pan]; 当手指拖动时调用 - (void)pan:(UIPanGestureRecognizer *)pan{拖动手势也有状态 if(pan.state == UIGestureRecognizerStateBegan){ 开始拖动 }else if(pan.state == UIGestureRecognizerStateChanged){ 注意:获取偏移量是相对于最原始的点 CGPoint transP = [pan translationInView:self.imageV]; self.imageV.transform = CGAffineTransformTranslate(self.imageV.transform, transP.x, transP.y); 复位,让它相对于上一次. [pan setTranslation:CGPointZero inView:self.imageV]; }else if(pan.state == UIGestureRecognizerStateEnded){ 结束拖动 } }

UIPinchGestureRecognizer(捏合手势，用于缩放)
UIRotationGestureRecognizer(旋转手势)

//现在视图上添加图片对图片进行操作 //添加捏合手势 UIPinchGestureRecognizer *pinGes = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinGes:)]; [self.imageView addGestureRecognizer:pinGes]; 旋转时调用 - (void)pinGes:(UIPinchGestureRecognizer *)pin{ self.imageView.transform = CGAffineTransformScale(self.imageV.transform, pin.scale, pin.scale); 复位 [pin setScale:1]; }添加旋转手势 UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)]; 设置代理使其能够同时支持多个手势(捏合的时候同时支持旋转) rotation.delegate = self; [self.imageView addGestureRecognizer:rotation]; 当手指开始旋转时调用. - (void)rotation:(UIRotationGestureRecognizer *)rotation{ self.imageView.transform = CGAffineTransformRotate(self.imageV.transform, rotation.rotation); 复位. [rotation setRotation:0]; }

三、手势的一些代理函数（UIGestureRecognizerDelegate）

// 是否允许开始触发手势 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer; //手指触摸屏幕后回调的方法，返回NO则不再进行手势识别，方法触发等 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch; //开始进行手势识别时调用的方法，返回NO则结束，不再触发手势 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer; //是否支持多时候触发，返回YES，则可以多个手势一起触发方法，返回NO则为互斥 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer; //下面这个两个方法也是用来控制手势的互斥执行的 //这个方法返回YES，第一个手势和第二个互斥时，第一个会失效 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer NS_AVAILABLE_IOS(7_0); //这个方法返回YES，第一个和第二个互斥时，第二个会失效 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer NS_AVAILABLE_IOS(7_0);

四、手势冲突处理一般在含有UIScrollView或者UIScrollView的子类的视图上添加自己的手势就会有冲突；利用UIGestureRecognizerDelegate中的代理方法可以解决相应的冲突；
因为在UIScrollView上有手势，利用

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer; //设置为YES就可以一直传递下去

同时手势与事件触摸有优先级的关系，使用手势时应该多注意