华山论剑之iOS手势（UIGestureRecognizer ）

子所不欲,勿施于人.

iOS系统在3.2版本之后提供了一些常用的手势,总共是6大手势,总共是六大类,当然了,当这些手势不能满足我们的工程需要的时候,我们需要自定义手势,这个手势类继承于UIGestureRecognizer这个类.

手势名称	手势类
点击手势	UITapGestureRecognizer
轻扫手势	UISwipeGestureRecognizer
长按手势	UILongPressGestureRecognizer
旋转手势	UIRotationGestureRecognizer
拖动手势	UIPanGestureRecognizer
捏合手势	UIPinchGestureRecognizer

UITapGestureRecognizer (点击手势)

点击手势比较简单,但是也是我们最常用的一种手势,我们只需要创建出手势并且添加到对应的视图上即可.

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAction:)];//tapAction:这个方法中我们添加当点击手势触发的时候,我们需要执行的方法

tapGesture.numberOfTapsRequired = 1; 
//点击次数

tapGesture.numberOfTouchesRequired = 1; 
//点击手指数

[self.view addGestureRecognizer:tapGesture];

UISwipeGestureRecognizer(轻扫手势)

轻扫手势当,有左右轻扫之分,所以我们可以区别对待,向左轻扫和向右轻扫

UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];

//设置轻扫的方向

swipeGesture.direction = UISwipeGestureRecognizerDirectionRight; 
//向右

[self.view addGestureRecognizer:swipeGesture];

UISwipeGestureRecognizer *swipeGestureLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];

//设置轻扫的方向

swipeGestureLeft.direction = UISwipeGestureRecognizerDirectionLeft; 
//向左

[self.view addGestureRecognizer:swipeGestureLeft];

//轻扫手势触发方法

下面的方法可以进行左右轻扫的设置.

-(void)swipeGesture:(id)sender
{
UISwipeGestureRecognizer *swipe = sender
if(swipe.direction == UISwipeGestureRecognizerDirectionLeft)   {      
//向左轻扫
   
  } if(swipe.direction == UISwipeGestureRecognizerDirectionRight){     
//向右轻扫    
  }

}

UILongPressGestureRecognizer(长按手势)

长按手势也是一种常用的手势,一般我们会用在图片上面,长按之后出现选项对话框,这时候,用户就可以进行进一步的用户交互了.

UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGesture:)];
//设置长按时间
longPressGesture.minimumPressDuration = 0.5;
[self.view addGestureRecognizer:longPressGesture];

//长按手势触发方法
-(void)longPressGesture:(id)sender
{
     UILongPressGestureRecognizer *longPress = sender;
     if (longPress.state == UIGestureRecognizerStateBegan)
     {
      
     }
}

长按手势的常用状态如下
开始：UIGestureRecognizerStateBegan
改变：UIGestureRecognizerStateChanged
结束：UIGestureRecognizerStateEnded
取消：UIGestureRecognizerStateCancelled
失败：UIGestureRecognizerStateFailed

UIPanGestureRecognizer (拖动手势)

拖动手势,也是一种常见的手势,我们一般用图标的拖动.

UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];
[self.view addGestureRecognizer:panGesture];

//拖动手势触发方法
-(void) panGesture:(id)sender
{
    UIPanGestureRecognizer *panGesture = sender;
    CGPoint movePoint = [panGesture translationInView:self.view];
    //your code
}

UIPinchGestureRecognizer (捏合手势)

捏合手势一般用于图片放大之后的还原

UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchGesture:)];
[self.view addGestureRecognizer:pinchGesture];
    ////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
        }];
    }
}

UIRotationGestureRecognizer (旋转手势)

旋转手势也是我们常见的一种手势之一

UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGesture:)];
[self.view addGestureRecognizer:rotationGesture];

//旋转手势触发方法
-(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
        }];
    }
}

注意:一个手势只能对应一个 View，但是一个 View 可以有多个手势。

原文参考:http://www.open-open.com/lib/view/open1435284827732.html