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
QQ.png
长按手势
QQ.png
捏合手势
QQ.png
旋转手势
QQ.png
轻扫手势
QQ.png
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。
QQ.png
QQ.png
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。
QQ.png
每一个手势都有对应的代理方法
QQ.png
QQ.png
QQ.png
QQ.png
QQ.png
- 同时支持多个手势
协议<UIGestureRecognizerDelegate>
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
QQ.png
QQ.png
代理方法
QQ.png
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);
}
