正确使用|正确使用 iOS 开发中的六大操作手势正确使用iOS开发中的六大操作

【正确使用|正确使用 iOS 开发中的六大操作手势】在 iOS 的开发过程中，我们一般使用 touches 方法来监听 view 的触摸事件，但是这样使用会有一些弊端：

必须得自定义 view, 在自定义的 View 当中去实现 touches 方法
由于是在 view 内部的 touches 方法中监听触摸事件，因此默认情况下，无法让其他外界对象监听 view 的触摸事件
不容易区分用户具体的手势行为

鉴于这些问题，在iOS 3.2 之后，苹果推出了手势识别功能（Gesture Recognizer）在触摸事件处理方面大大简化了开发者的开发难度。
UIGestureRecognizer 手势识别器

利用 UIGestureRecognizer，能轻松识别用户在某个 view 上面做的一些常见手势
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
1. 点按手势 UITapGestureRecognizer
2. 长按手势 UILongPressGestureRecognizer
3. 平移（拖拽）手势 UIPanGestureRecognizer
4. 轻扫手势 UISwipeGestureRecognizer
5. 旋转手势 UIRotationGestureRecognizer
6. 捏合手势 UIPinchGestureRecognizer
手势的使用方法
1. 创建手势
2. 添加手势
3. 实现手势方法
4. 补充（手势也可以设置代理）

1. UITapGestureRecognizer 点按手势

文章图片
点按手势效果图

- (void)topGes { //创建点按手势 UITapGestureRecognizer *tapGes = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap)]; //手势也可以设置代理 tapGes.delegate = self; //添加手势 [self.imageView addGestureRecognizer:tapGes]; }- (void)tap { NSLog(@"现在是点按手势"); }

实现代理方法

//代理方法：是否允许接收手指 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch { //让图片左边可以点击，右边不能点击 //获取当前手指所在的点进行判断 CGPoint curP = [touch locationInView:self.imageView]; if (curP.x > self.imageView.bounds.size.width * 0.5) { return NO; }else { return YES; } }

2. UILongPressGestureRecognizer 长按手势

文章图片
长按手势效果图

- (void)longPGes { UILongPressGestureRecognizer *longPGes = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longP:)]; [self.imageView addGestureRecognizer:longPGes]; }//当长按并移动时，会多次调用这个方法 - (void)longP:(UILongPressGestureRecognizer *)longP { //判断长按时的状态 if (longP.state == UIGestureRecognizerStateBegan) { NSLog(@"开始长按"); }else if (longP.state == UIGestureRecognizerStateChanged) { NSLog(@"- - - 长按时手指移动了 - - -"); }else if (longP.state == UIGestureRecognizerStateEnded) { NSLog(@"长按结束"); } }

3. UIPanGestureRecognizer 平移（拖拽）手势平移（拖拽）手势效果图

- (void)panGes { UIPanGestureRecognizer *panGes = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)]; [self.imageView addGestureRecognizer:panGes]; }- (void)pan:(UIPanGestureRecognizer *)pan { //获取偏移量 CGPoint transP = [pan translationInView:self.imageView]; NSLog(@"transP = %@", NSStringFromCGPoint(transP)); //移动图片 self.imageView.transform = CGAffineTransformTranslate(self.imageView.transform, transP.x, transP.y); //清零,不要累加 [pan setTranslation:CGPointZero inView:self.imageView]; }

4. UISwipeGestureRecognizer 轻扫手势

文章图片
轻扫手势效果图

一个手势只能对应一个方向，若要支持多个方向，可以添加多个手势
轻扫手势的方向默认是向右
可以通过修改手势的 direction 属性修改手势的方向

- (void)swipeGes { //一个手势只能对应一个方向，若要支持多个方向，可以添加多个手势 UISwipeGestureRecognizer *swipeGes1 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)]; //轻扫手势的方向默认是向右 [self.imageView addGestureRecognizer:swipeGes1]; UISwipeGestureRecognizer *swipeGes2 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)]; //可以修改手势的方向，向上 swipeGes2.direction = UISwipeGestureRecognizerDirectionUp; [self.imageView addGestureRecognizer:swipeGes2]; UISwipeGestureRecognizer *swipeGes3 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)]; //手势的方向，向左 swipeGes3.direction =UISwipeGestureRecognizerDirectionLeft; [self.imageView addGestureRecognizer:swipeGes3]; UISwipeGestureRecognizer *swipeGes4 = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)]; //手势的方向，向下 swipeGes4.direction = UISwipeGestureRecognizerDirectionDown; [self.imageView addGestureRecognizer:swipeGes4]; }- (void)swipe:(UISwipeGestureRecognizer *)swipe { if (swipe.direction == UISwipeGestureRecognizerDirectionLeft) { NSLog(@"向左轻扫 --- left"); }else if (swipe.direction == UISwipeGestureRecognizerDirectionRight){ NSLog(@"向右轻扫 --- right"); }else if (swipe.direction == UISwipeGestureRecognizerDirectionUp){ NSLog(@"向上轻扫 --- up"); } else if (swipe.direction == UISwipeGestureRecognizerDirectionDown) { NSLog(@"向下轻扫 --- down"); } }

5. UIRotationGestureRecognizer 旋转手势旋转手势效果图

- (void)rotationGes { UIRotationGestureRecognizer *rotationGes = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)]; [self.imageView addGestureRecognizer:rotationGes]; }- (void)rotation:(UIRotationGestureRecognizer *)rotationGes { //获取旋转的度数 CGFloat angle = rotationGes.rotation; //旋转图片 self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, angle); //清零 [rotationGes setRotation:0]; }

6. UIPinchGestureRecognizer 捏合手势捏合手势效果图

- (void)pinchGes { UIPinchGestureRecognizer *pinchGes = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)]; [self.imageView addGestureRecognizer:pinchGes]; }- (void)pinch:(UIPinchGestureRecognizer *)pinchGes { //获取缩放比例 CGFloat scale = pinchGes.scale; NSLog(@"scale = %f", scale); //缩放图片 self.imageView.transform = CGAffineTransformScale(self.imageView.transform, scale, scale); //初始化大小 [pinchGes setScale:1]; }

补充：手势的混合使用

默认情况下只能同时支持一种手势
若要同时支持多种手势，可以给要支持的手势设置代理，并实现以下代理方法

//是否允许同时支持多个手势 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizershouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {return YES; }

旋转与捏合混合手势使用效果图