ios 手势的基本使用

手势类型

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。其子类有：

UITapGestureRecognizer（敲击）
UIPinchGestureRecognizer（捏合，用于缩放）
UIPanGestureRecognizer（拖拽）
UISwipeGestureRecognizer（轻扫）
UIRotationGestureRecognizer（旋转）
UILongPressGestureRecognizer（长按）

属性state

另外，UIGestureRecognizer类中有一个属性state，表示手势的当前状态，如开始、正在..中、结束等。其子类也继承了这个属性，有以下状态：

UIGestureRecognizerStatePossible、Began、Changed、Ended、Cancelled、Failed。

基本使用

要什么手势，就创建什么手势的对象，同时设置监听方法（自定义），然后添加给对应控件，如：

点击手势

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长按手势

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捏合手势

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旋转手势

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轻扫手势

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PS: 一个轻扫手势只能有一个方向。若要有多个方向，则再添加轻扫对象，不同方向的轻扫可以设对应的操作。

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注意：UIImageView默认不能与用户交互。

• 手势还可以添加代理
  点按tap、常按longPress（移动时也会持续调用）、轻扫swipe、拖到pan、捏合pinch、旋转Rotation。

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每一个手势都有对应的代理方法

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• 同时支持多个手势
  协议
  设代理(要同时支持哪些手势，就把相关的手势对象设置代理

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代理方法

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应用举例

• 实现图片拖动、缩放、旋转。（亲测可用）

#pragma mark - 添加 Imgview
-(void)addMaskImageView{
    
    UIImageView *Imgv = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"manHair1"]];
    Imgv.clipsToBounds = YES;
    Imgv.hidden = YES;
    Imgv.userInteractionEnabled = YES;
    [_personBackImgV addSubview:Imgv];
    _maskImgV = Imgv;
    double m = 150/_maskImgV.image.size.width;
    _maskImgV.frame = CGRectMake(20, 100, 150, _maskImgV.image.size.height*m);
    
    //添加拖到、旋转、缩放 手势
    UIPanGestureRecognizer *gesture1 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(onDrag:)];
    [_maskImgV addGestureRecognizer:gesture1];

    UIRotationGestureRecognizer *gesture2 = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(onRotating:)];
    [_maskImgV addGestureRecognizer:gesture2];

    UIPinchGestureRecognizer *gesture3 = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(onScale:)];
    [_maskImgV addGestureRecognizer:gesture3];
    
}

#pragma mark - 缩放图片 处理
-(void)onScale:(UIPinchGestureRecognizer*)gesture{
    
    gesture.view.transform = CGAffineTransformScale(gesture.view.transform, gesture.scale, gesture.scale);
    gesture.scale = 1;
}

#pragma mark - 旋转图片 处理
-(void)onRotating:(UIRotationGestureRecognizer*)gesture{
    
    gesture.view.transform = CGAffineTransformRotate(gesture.view.transform, gesture.rotation);
    gesture.rotation = 0;
}

#pragma mark - 移动图片 处理
-(void)onDrag:(UIPanGestureRecognizer*)gesture{
    
    CGPoint translation = [gesture translationInView:self.view];
    CGPoint center = gesture.view.center;
    center.x += translation.x;
    center.y += translation.y;
    gesture.view.center = center;
    [gesture setTranslation:CGPointZero inView:self.view];
    
//    if (gesture.state == UIGestureRecognizerStateEnded){
//        //UIGestureRecognizerStateBegan /UIGestureRecognizerStateChanged
//
//    }
}

• 实现单手旋转，缩放图片

    UIImageView *Imgv = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"manHair1"]];
    Imgv.clipsToBounds = NO;
    Imgv.hidden = YES;
    Imgv.userInteractionEnabled = YES;
    [_personBackImgV addSubview:Imgv];
    _maskImgV = Imgv;
    double m = 150/_maskImgV.image.size.width;
    _maskImgV.frame = CGRectMake(20, 100, 150, _maskImgV.image.size.height*m);
    
    //添加拖到手势
    UIPanGestureRecognizer *gesture1 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(onDrag:)];
    [_maskImgV addGestureRecognizer:gesture1];
    
    UIImageView *imgvCtrl = [[UIImageView alloc] init];
    imgvCtrl.image = [UIImage imageNamed:@"52px红"];
    imgvCtrl.userInteractionEnabled = YES;
    [_maskImgV addSubview:imgvCtrl];
    _imgvCtrl = imgvCtrl;
    [_imgvCtrl mas_makeConstraints:^(MASConstraintMaker *make) {
        make.bottom.right.equalTo(_maskImgV).offset(15);
        make.width.height.equalTo(@30);
    }];
    
    UIPanGestureRecognizer *gesture5 = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(onScaleAndRotate:)];
    [_imgvCtrl addGestureRecognizer:gesture5];

//   手势回调方法
-(void)onScaleAndRotate:(UIPanGestureRecognizer*)gesture{
    
    UIView *viewCtrl = gesture.view;
    UIView *viewImg = _maskImgV;
    
    CGPoint center = viewImg.center;
    CGPoint prePoint = viewCtrl.center;
    CGPoint translation = [gesture translationInView:gesture.view];
    CGPoint curPoint = CGPointMake(prePoint.x+translation.x, prePoint.y+translation.y);
    
    // 计算缩放
    CGFloat preDistance = [self getDistance:prePoint withPointB:center];
    CGFloat curDistance = [self getDistance:curPoint withPointB:center];
    CGFloat scale = curDistance / preDistance;
    
    // 计算弧度
    CGFloat preRadius = [self getRadius:center withPointB:prePoint];
    CGFloat curRadius = [self getRadius:center withPointB:curPoint];
    CGFloat radius = curRadius - preRadius;
    radius = - radius;
    
    CGAffineTransform transform = CGAffineTransformScale(viewImg.transform, scale, scale);
    viewImg.transform = CGAffineTransformRotate(transform, radius);
    
    [gesture setTranslation:CGPointZero inView:viewCtrl];
}

-(CGFloat)getDistance:(CGPoint)pointA withPointB:(CGPoint)pointB{
    CGFloat x = pointA.x - pointB.x;
    CGFloat y = pointA.y - pointB.y;
    
    return sqrt(x*x + y*y);
}

-(CGFloat)getRadius:(CGPoint)pointA withPointB:(CGPoint)pointB{
    CGFloat x = pointA.x - pointB.x;
    CGFloat y = pointA.y - pointB.y;
    return atan2(x, y);
}

参考资料

http://blog.csdn.net/luguogege/article/details/50611283