UIGestureRecognizer是一个定义基本手势的抽象类：

1、拍击UITapGestureRecognizer (任意次数的拍击)

2、向里或向外捏UIPinchGestureRecognizer (用于缩放)

3、摇动或者拖拽UIPanGestureRecognizer (拖动)

4、擦碰UISwipeGestureRecognizer (以任意方向)

5、旋转UIRotationGestureRecognizer (手指朝相反方向移动)

6、长按UILongPressGestureRecognizer (长按)

1 首先建立一个要拖动的控件

UIButton *btn = [[UIButton alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];

btn.backgroundColor = [UIColor redColor];

[self.view addSubview:btn];

2 添加拖动手势

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];//创建手势

[btn setUserInteractionEnabled:YES]; //设置启用用户交互

[btn addGestureRecognizer:pan];//把手势添加到控件

- (void) handlePan: (UIPanGestureRecognizer *)rec{

// NSLog(@"xxoo---xxoo---xxoo");

CGPoint point = [rec translationInView:self.view];

//该方法返回在横坐标上、纵坐标上拖动了多少像素

NSLog(@"%f,%f",point.x,point.y);

rec.view.center = CGPointMake(rec.view.center.x + point.x, rec.view.center.y + point.y);

//rec.view 指的是把rec添加到那个控件上的

// 因为拖动起来一直是在递增，所以每次都要用setTranslation:方法制0这样才不至于不受控制般滑动出视图

[rec setTranslation:CGPointMake(0, 0) inView:self.view];

}

3添加缩放手势

//缩放

UIPinchGestureRecognizer *ping = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];

[btn setUserInteractionEnabled:YES]; //设置启用用户交互

[btn addGestureRecognizer:ping];

-(void) handlePinch:(UIPinchGestureRecognizer *)rec

{

NSLog(@" recognizer.scale------%f",rec.scale

);//缩放的倍数，

// view.transform 为原来的 状态；

rec.view.transform=CGAffineTransformScale(rec.view.transform, rec.scale,rec.scale);

}