码迷,mamicode.com
首页 > 移动开发 > 详细

iOS手势识别

时间:2016-04-10 18:05:50      阅读:216      评论:0      收藏:0      [点我收藏+]

标签:

 

一、手势识别与触摸事件

 

1、如果想监听一个view上面的触摸事件,可选的做法是:

(1)自定义一个view

(2)实现view的touches方法,在方法内部实现具体处理代码

 

2、通过touches方法监听view触摸事件,有很明显的几个缺点

 

(1)必须得自定义view

(2)由于是在view内部的touches方法中监听触摸事件,因此默认情况下,无法让其他外界对象监听view的触摸事件

(3)不容易区分用户的具体手势行为

 

3、iOS 3.2之后,苹果推出了手势识别功能(Gesture Recognizer),在触摸事件处理方面,大大简化了开发者的开发难度

 

 

二、手势识别——Gesture Recognizer

 

1、手势识别器:UIGestureRecognizer

 

(1)UIGestureRecognizer是一个抽象类,定义了所有手势的基本行为,使用它的子类才能处理具体的手势

(2)子类的继承和功能

图示:

 技术分享

 

2、手势识别的使用方法及步骤

 

(1)创建手势识别实例

(2)设置手势识别属性,例如手指数量,方向等

(3)将手势识别附加到指定的视图之上

(4)编写手势触发监听方法

(5)手势触发监听方法后,要还原手势识别实例的属性,比如:获取了缩放比例,然后给某个控件进行了缩放,最后再把缩放比例还原为1。这样后续的手势操作会从新开始,避免错误

 

3、手势识别的状态

 

(1)类似于触摸事件,手势识别实例包含了属性 state,可以区别此时手势的状态

(2)state属性为枚举类型:

 

   <1> 没有触摸事件发生,所有手势识别的默认状态

    UIGestureRecognizerStatePossible,

 

    <2> 一个手势已经开始但尚未改变或者完成时

    UIGestureRecognizerStateBegan, (类似于 touchesBegan)

 

    <3> 手势状态改变

    UIGestureRecognizerStateChanged, (类似于 touchesMoved)

 

    <4> 手势完成

    UIGestureRecognizerStateEnded, (类似于 touchesEnded)

 

    <5> 手势取消,恢复至Possible状态

    UIGestureRecognizerStateCancelled, (比如手指按下按钮,然后从其他地方抬起)

 

    <6> 手势失败,恢复至Possible状态

    UIGestureRecognizerStateFailed,

 

    <7> 识别到手势结束

    UIGestureRecognizerStateRecognized = UIGestureRecognizerStateEnded

 

4、不同手势识别子类具有不同的属性或方法,几个重要的举例如下:

 

(1)在“轻点”手势中: 

 

  <1> 需要连续敲击2次触发手势

  tap.numberOfTapsRequired = 2;

 

  <2> 需要2根手指一起敲击

  tap.numberOfTouchesRequired = 2;

 

(2)在“旋转”手势中:

 

  <1>获取用户旋转角度 

  CGFloat rotation;

   

  <2>获取用户旋转速度

   CGFloat velocity

 

(3)在“轻扫”手势中:

   <1>扫动的方向,注意,一个轻扫手势识别对象,只能对应一个扫动方向

   UISwipeGestureRecognizerDirection

 

(4)在“拖拽”手势中:

   <1> 获取移动的距离 ,这个是对象方法

   - (CGPoint)translationInView:(nullable UIView *)view; 

 

  <2>清除手势移动的距离(为了下次手势事件的正确计算)

    例: [pan setTranslation:CGPointZero inView:self.view];

 

 

5、实现多手势识别(比如缩放的同时可以旋转)

 

(1)设置手势识别器的代理

  

(2)实现相应的代理方法,支持多手势识别。

 

 

三、demo实例

 

1、图示

 技术分享

 

2、贴出部分代码

 

#pragma mark - 长按手势
- (IBAction)longPressBtnClick:(id)sender {
    
    //长按手势识别器,正常下会执行两次方法,不晓得为啥     
    UILongPressGestureRecognizer * longPress = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longClick:)];
    
    [self.view addGestureRecognizer:longPress];
    //代理
    longPress.delegate = self;
    
}

-(void)longClick:(UILongPressGestureRecognizer *)longPress
{

    //根据状态判断
    if(longPress.state==UIGestureRecognizerStateBegan)
    {
        NSLog(@"开始长按了~~");

    }
    
}

#pragma mark - 旋转手势
- (IBAction)rotateBtnClick {
 
    UIRotationGestureRecognizer * rotate = [[UIRotationGestureRecognizer alloc]initWithTarget:self action:@selector(rotateClick:)];
    
    [self.view addGestureRecognizer:rotate];
    
    //增加代理
     rotate.delegate =self;
      
}

-(void)rotateClick:(UIRotationGestureRecognizer *)rotate
{

    CGFloat ratation = rotate.rotation;
    self.headerView.transform = CGAffineTransformRotate(self.headerView.transform, ratation);

    //清除掉累加的 rotation
    rotate.rotation=0;
}




#pragma mark - 缩放手势
- (IBAction)pinchBtnClick {
    
    UIPinchGestureRecognizer * pinch = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchClick:)];
    
    [self.view addGestureRecognizer:pinch];
    
    //增加代理
    pinch.delegate = self;
    
}


-(void)pinchClick:(UIPinchGestureRecognizer *)pinch
{
    CGFloat scale = pinch.scale;
    self.headerView.transform = CGAffineTransformScale(self.headerView.transform, scale, scale);
    
    //同样清除
    pinch.scale = 1;

}




#pragma mark - 轻扫手势
- (IBAction)swipeBtnClick {

    UISwipeGestureRecognizer * swipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeClick:)];
    
    //向右扫动手势
    swipe.direction= UISwipeGestureRecognizerDirectionRight;
    [self.view addGestureRecognizer:swipe];
    
    UISwipeGestureRecognizer * swipe2 =[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeClick:)];
    
    //向左扫动手势
    swipe2.direction= UISwipeGestureRecognizerDirectionLeft;
    [self.view addGestureRecognizer:swipe2];
}

-(void)swipeClick:(UISwipeGestureRecognizer *)swipe
{

    if (swipe.direction==UISwipeGestureRecognizerDirectionRight) {    
        [UIView animateWithDuration:0.3 animations:^{
       
        self.headerView.transform = CGAffineTransformTranslate(self.headerView.transform, 100, 0);
            
            
        }completion:^(BOOL finished) {
            
            [UIView animateWithDuration:0.5 animations:^{
                self.headerView.transform = CGAffineTransformIdentity;
                
            }];
            
            
        }];
     
    }
    else if (swipe.direction==UISwipeGestureRecognizerDirectionLeft) {
    
        [UIView animateWithDuration:0.3 animations:^{
            
                self.headerView.transform = CGAffineTransformTranslate(self.headerView.transform, -100, 0);          
            
        }completion:^(BOOL finished) {
            
            [UIView animateWithDuration:0.5 animations:^{
                self.headerView.transform = CGAffineTransformIdentity;

            }];
        }];
    }
}




#pragma mark - 拖拽手势
- (IBAction)panBtnClick {
  
    UIPanGestureRecognizer * pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panClick:)];
    
    [self.view addGestureRecognizer:pan];
     
}


-(void)panClick:(UIPanGestureRecognizer *)pan
{
    CGPoint point = [pan translationInView:self.view];
    
    self.headerView.transform = CGAffineTransformTranslate(self.headerView.transform, point.x, point.y);

    [pan setTranslation:CGPointZero inView:self.view];
}


//手势识别代理实现
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;

}

 

iOS手势识别

标签:

原文地址:http://www.cnblogs.com/cleven/p/5374644.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!