iOS开发之手势篇

手势就是有规律的触摸.

UIGestureRecognizer 代表iOS中的手势类,是具体手势类的父类.

共有6个手势类分别是:1.点击 2.长按 3.轻扫 4.旋转 5.捏合 6.拖拽

1). UITapGestureRecognizer (点击手势)

创建一个点击手势

       UITapGestureRecognizer *tap = [[UITapGestureRecognizeralloc]initWithTarget:selfacti on:@selector(changeBrackgroud:)];

//          触发谁的(self指当前类的对象)     什么方法(改变背景颜色的方法)

    [self.viewaddGestureRecognizer:tap];

    // 向视图添加tap 这个点击手势(当前tap的引用计数为2)

    [taprelease];

    // (引用计数减一)

- (void)changeBrackground:(UIGestureRecognizer *)tap

// tap 触发的方法(改变背景颜色) 形参的类型是UIGestureRecognizer

{

   UIView *aView = tap.view;

    // tap.view 获取当前点击手势所在的视图

    aView.backgroundColor = [UIColorcolorWithRed:arc4random() %256 / 255.0 green:arc4random() %256 /255.0blue:arc4random() %256 /255.0alpha:1.0];

    //其中用到了三基色调色的方法,其中每个值的取值范围都是0 ~ 1,而基色的取值范围是0 ~ 255, 所以要除以255.0, (alpha表示透明度 0 ~ 1)

}

UITapGestureRecognizer 其中的属性

    numberOfTapsRequired点击几次才会触发事件 (默认值是1)

    tap.numberOfTapsRequired =2;//点击2次触发

    

    numberOfTouchesRequired需要几个手指点击 (默认值是1)

    tap.numberOfTouchesRequired =2;//需要两个手指点击

2).UILongPressGestureRecognizer

    // 创建长按手势

    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizeralloc]initWithTarget:selfaction:@selector(changeBrackground:)];

    //为视图添加长按手势 (默认响应时间是0.5s)

    // 设置响应时间

    longPress.minimumPressDuration =2;//两秒之后才触发

    [self.viewaddGestureRecognizer:longPress];

    [longPressrelease];

手势的四个状态

    UIGestureRecognizerState//状态

     UIGestureRecognizerStateCancelled//取消

    UIGestureRecognizerStateCancelled//失败

    UIGestureRecognizerStateBegan//开始

    UIGestureRecognizerStateChanged//改变

例:

 

    //在手势开始的时候改变背景颜色

    if (tap.state == UIGestureRecognizerStateBegan) {

        aView.backgroundColor = [UIColor colorWithRed:arc4random() %256 /255.0 green:arc4random() %256 /255.0 blue:arc4random() %256 /255.0 alpha:1.0];

        }

3). UISwipeGestureRecognizer (轻扫手势)

    direction// 轻扫的方向 (默认从左向右轻扫, 每个手势只能加一个方向)

    UISwipeGestureRecognizerDirectionRight  // 向右

    UISwipeGestureRecognizerDirectionLeft  // 向左

    UISwipeGestureRecognizerDirectionUp    // 向上

    UISwipeGestureRecognizerDirectionDown   // 向下

   

    // 创建清扫手势

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

 swipe.direction = UISwipeGestureRecognizerDirectionDown;// 向下轻扫

    // 添加清扫手势

    [self.viewaddGestureRecognizer:swipe];

    [swiperelease];

4). UIPanGestureRecognizer (拖拽手势)  

 // 创建拖拽手势

    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizeralloc]initWithTarget:selfaction:@selector(panAction:)];

      // 添加手势

    [viewaddGestureRecognizer:pan];

    

    [panrelease];

// 手势触发的方法

- (void)panAction:(UIPanGestureRecognizer *)pan

{

    //基于手指的起始点的偏移量

   CGPoint  point = [pantranslationInView:pan.view];

    //当前视图偏移量跟随手指移动而一块移动

    pan.view.transform =CGAffineTransformMakeTranslation(point.x, point.y);

}

5).UIPinchGestureRecognizer (捏合手势)

    

    // 创建捏合手势

    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizeralloc]initWithTarget:selfaction:@selector(pinchAction:)];

    // 添加手势

    [viewaddGestureRecognizer:pinch];

    [pinchrelease];

- (void)pinch:(UIPinchGestureRecognizer *)pinch

{

    pinch.scale//缩放比例

    //将视图进行等比例放大

    pinch.view.transform =CGAffineTransformMakeScale(pinch.scale, pinch.scale);

}

6).UIRotationGestureRecognizer (旋转手势)

    // 创建旋转手势

    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizeralloc]initWithTarget:selfaction:@selector(rotationAction:)];

    // 添加旋转手势

    [viewaddGestureRecognizer:rotation];

    [rotationrelease];

    

}

- (void)rotationAction:(UIRotationGestureRecognizer *)rotation

{

    // 让view旋转                       旋转角度      rotation 是旋转手势里的旋转角度属性;

    rotation.view.transform =CGAffineTransformMakeRotation(rotation.rotation);

}