iOS开发教程之手势识别方法

jopen 9年前

感觉有必要把iOS开发中的手势识别做一个小小的总结。在上一篇iOS开发之自定义表情键盘(组件封装与自动布局)博客中用到了一个轻击手势,就是 在轻击TextView时从表情键盘回到系统键盘,在TextView中的手是用storyboard添加的。下面会先给出如何用storyboard给 相应的控件添加手势,然后在用纯代码的方式给我们的控件添加手势,手势的用法比较简单。和button的用法类似,也是目标动作回调,话不多说,切入今天 的正题。总共有六种手势识别:轻击手势(TapGestureRecognizer),轻扫手势(SwipeGestureRecognizer), 长按手势(LongPressGestureRecognizer), 拖动手势(PanGestureRecognizer), 捏合手势(PinchGestureRecognizer),旋转手势(RotationGestureRecognizer);

其实这些手势用touche事件完全可以实现,苹果就是把常用的触摸事件封装成手势,来提供给用户。读者完全可以用TouchesMoved来写拖动手势等

一,用storyboard给控件添加手势识别,当然啦用storyboard得截张图啦

1.用storyboard添加手势识别,和添加一个Button的步骤一样,首先我们得找到相应的手势,把手势识别的控件拖到我们要添加手势的控件中,截图如下

iOS开发教程之手势识别方法

2.给我们拖出的手势添加回调事件,和给Button回调事件没啥区别的,在回调方法中添加要实现的业务逻辑即可,截图如下:

iOS开发教程之手势识别方法

    二,纯代码添加手势识别

用storyboard可以大大简化我们的操作,不过纯代码的方式还是要会的,就像 要Dreamwear编辑网页一样(当然啦,storyboard的拖拽功能要比Dreamwear的拖拽强大的多),用纯代码敲出来的更为灵活,更加便 于维护。不过用storyboard可以减少我们的工作量,这两个要配合着使用才能大大的提高我们的开发效率。个人感觉用storyboard把框架搭起 来(Controller间的关系),一下小的东西还是用纯代码敲出来更好一些。下面就给出如何给我们的控件用纯代码的方式来添加手势识别。

1.轻击手势(TapGestureRecognizer)的添加

初始化代码TapGestureRecongnizer的代码如下:

     //新建tap手势        UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGesture:)];        //设置点击次数和点击手指数        tapGesture.numberOfTapsRequired = 1; //点击次数        tapGesture.numberOfTouchesRequired = 1; //点击手指数        [self.view addGestureRecognizer:tapGesture];

在回调方法中添加相应的业务逻辑:

 //轻击手势触发方法    -(void)tapGesture:(id)sender    {        //轻击后要做的事情            }

2.长按手势(LongPressGestureRecognizer)

初始化代码:

//添加长摁手势        UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGesture:)];        //设置长按时间        longPressGesture.minimumPressDuration = 0.5; //(2秒)        [self.view addGestureRecognizer:longPressGesture];

在对应的回调方法中添加相应的方法(当手势开始时执行):

 //常摁手势触发方法    -(void)longPressGesture:(id)sender    {        UILongPressGestureRecognizer *longPress = sender;        if (longPress.state == UIGestureRecognizerStateBegan)       {            UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"提示" message:@"长按触发" delegate:nil cancelButtonTitle:@"取消" otherButtonTitles: nil];            [alter show];        }    }

代码说明:手势的常用状态如下

开始:UIGestureRecognizerStateBegan

改变:UIGestureRecognizerStateChanged

结束:UIGestureRecognizerStateEnded

取消:UIGestureRecognizerStateCancelled

失败:UIGestureRecognizerStateFailed

3.轻扫手势(SwipeGestureRecognizer)

在初始化轻扫手势的时候得指定轻扫的方向,上下左右。 如果要要添加多个轻扫方向,就得添加多个轻扫手势,不过回调的是同一个方法。

添加轻扫手势,一个向左一个向右,代码如下:

     //添加轻扫手势         UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];         //设置轻扫的方向         swipeGesture.direction = UISwipeGestureRecognizerDirectionRight; //默认向右         [self.view addGestureRecognizer:swipeGesture];           //添加轻扫手势         UISwipeGestureRecognizer *swipeGestureLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];         //设置轻扫的方向        swipeGestureLeft.direction = UISwipeGestureRecognizerDirectionLeft; //默认向右        [self.view addGestureRecognizer:swipeGestureLeft];

回调方法如下:

 //轻扫手势触发方法     -(void)swipeGesture:(id)sender     {         UISwipeGestureRecognizer *swipe = sender;         if (swipe.direction == UISwipeGestureRecognizerDirectionLeft)         {             //向左轻扫做的事情         }         if (swipe.direction == UISwipeGestureRecognizerDirectionRight)        {            //向右轻扫做的事情        }    }

4.捏合手势(PinchGestureRecognizer)

捏合手势初始化

  //添加捏合手势        UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchGesture:)];        [self.view addGestureRecognizer:pinchGesture];

捏合手势要触发的方法(放大或者缩小图片):

  ////捏合手势触发方法     -(void) pinchGesture:(id)sender     {          UIPinchGestureRecognizer *gesture = sender;           //手势改变时         if (gesture.state == UIGestureRecognizerStateChanged)         {             //捏合手势中scale属性记录的缩放比例            _imageView.transform = CGAffineTransformMakeScale(gesture.scale, gesture.scale);        }          //结束后恢复        if(gesture.state==UIGestureRecognizerStateEnded)        {            [UIView animateWithDuration:0.5 animations:^{                _imageView.transform = CGAffineTransformIdentity;//取消一切形变            }];        }    }

5.拖动手势(PanGestureRecognizer)

拖动手势的初始化

//添加拖动手势        UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];        [self.view addGestureRecognizer:panGesture];

拖动手势要做的方法(通过translationInView获取移动的点,和TouchesMoved方法类似)

 //拖动手势    -(void) panGesture:(id)sender    {        UIPanGestureRecognizer *panGesture = sender;          CGPoint movePoint = [panGesture translationInView:self.view];          //做你想做的事儿    }

6.旋转手势(RotationGestureRecognizer)

旋转手势的初始化

//添加旋转手势        UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGesture:)];        [self.view addGestureRecognizer:rotationGesture];

旋转手势调用的方法:

  //旋转手势     -(void)rotationGesture:(id)sender     {           UIRotationGestureRecognizer *gesture = sender;           if (gesture.state==UIGestureRecognizerStateChanged)         {             _imageView.transform=CGAffineTransformMakeRotation(gesture.rotation);        }          if(gesture.state==UIGestureRecognizerStateEnded)        {              [UIView animateWithDuration:1 animations:^{                _imageView.transform=CGAffineTransformIdentity;//取消形变            }];        }      }
来源: 清风玉露一相逢