IOS 触摸与手势

触摸

响应者对象

在iOS中不是任何对象都能处理事件,只有继承了UIResponder的对象才能接收并处理事件.我们称之为"响应者对象".

UIApplication,UIViewController,UIView都继承自UIResponder,因此它们都是响应者对象,都能够接收并处理事件.

UIView??????不接受触摸时间的三种情况??????????????????

• •  ????不接受用户交互????????????userInteractionEnable = NO;??（例如：UILabel与UIImageView????这些控件userInteractionEnable默认为??????NO因此这些控件默认是不能接受触摸事件的）
• •  ??隐藏：??hidden=YES;
• •  透明：????alpha=0.0~0.01

  ????响应触摸的方法，可以通过UIResponder如下的四个方法来实现

  •  -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;????????????????

  //当用户开始触摸时触发该方法

  •  -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;????????????????????//当用户手指开始移动时触发该方法

  •  -(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;??????????//当用户触摸结束时触发该方法

  •  -(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent*)event;??????????????????????????????//当系统事件（比如内存不足，电话呼入）终止了触摸事件时激发该方法

  //当用户开始触摸时触发该方法
  - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event
  
  {
      NSArray *touchArr = [touches allObjects];//获取用户开始触摸时手指的数量
  
      UITouch *touch = [touchArr objectAtIndex:0];
  
      CGPoint point = [touch locationInView:[touch view]]; //获取开始触摸时手指的位置
  
  //    NSLog(@"%d",touch.tapCount);//获取手指短时间内点击的次数
  
      if (touch.tapCount == 1) {
          [self performSelector:@selector(tapOne) withObject:nil afterDelay:0.5];
          //延迟0.5秒调用方法tapOne
  
      }
      if (touch.tapCount == 2) {
          //如果用户要只是响应双击,销毁延迟调用
          [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(tapOne) object:nil];
      }
  
  }
  
  -(void)tapOne
  {
      NSLog(@"点击一次");
  }
  //当用户手指开始移动时触发该方法
  - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event
  {
      NSLog(@"手指移动");
  }
  //当用户触摸结束时触发该方法
  - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event
  {
      NSLog(@"触摸手势结束");
  }
  //当系统事件（比如内存不足，电话呼入）终止了触摸事件时激发该方法
  - (void)touchesCancelled:(nullable NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event
  {
  
  }
  

  手势

  UITapGestureRecognizer   点击

   label = [[UILabel alloc]initWithFrame:CGRectMake(self.view.bounds.size.width/2-50, self.view.bounds.size.height/2-50, 100, 100)];
      label.backgroundColor = [UIColor greenColor];
      label.userInteractionEnabled = YES;
      [self.view addSubview:label];
  
      UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapGestureHandle:)];
      tapGesture.numberOfTapsRequired = 1; //需要点击的次数
      tapGesture.numberOfTouchesRequired = 1; //需要1根手指点击
      [label addGestureRecognizer:tapGesture];

  -(void)tapGestureHandle:(UITapGestureRecognizer *)gesture
  {
      NSLog(@"点击触发");
      CGPoint point = [gesture locationInView:self.view]; //获取点击坐标
  //
  }

  UIPinchGestureRecognizer  捏合

     UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(pinchGestureHandle:)];
      label.multipleTouchEnabled = YES; //允许支持多点触摸
      [label addGestureRecognizer:pinchGesture];
      

  -(void)pinchGestureHandle:(UIPinchGestureRecognizer *)gesture
  {
      CGFloat scale = gesture.scale; //获取用户捏合比例
      CGFloat velocity = gesture.velocity;  //获取用户捏合速度
      label.transform = CGAffineTransformScale(label.transform, scale, scale);
      gesture.scale = 1.0;
  
  }

  UIPanGestureRecognizer   拖拽

     UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(panGestureHandle:)];
      panGesture.maximumNumberOfTouches = 1; //允许该收拾处理器最多支持几个手指拖动
      panGesture.minimumNumberOfTouches = 1;//允许该收拾处理器最少支持几个手指拖动
      [label addGestureRecognizer:panGesture];

  -(void)panGestureHandle:(UIPanGestureRecognizer *)gesture
  {
      CGPoint point = [gesture translationInView:label]; // 获取控件位移
      label.transform = CGAffineTransformTranslate(label.transform, point.x, point.y);
      [gesture setTranslation:CGPointMake(0, 0) inView:label];
  
  }

  UISwipeGestureRecognizer  轻扫

  由于一个控件指甲一次轻扫手势只支持一个方向上的轻扫，如果需要四个方向上的轻扫手势，需要加四次

   for (int i = 0; i < 4; i ++) {
          UISwipeGestureRecognizer *swipGesture = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipGestureHandle:)];
          swipGesture.numberOfTouchesRequired = 1;
          swipGesture.direction = 1 << i;
          [label addGestureRecognizer:swipGesture];
      }

  -(void)swipGestureHandle:(UISwipeGestureRecognizer *)gesture
  {
      if (gesture.direction == UISwipeGestureRecognizerDirectionRight) {
          NSLog(@"向右轻扫");
      }
      if (gesture.direction == UISwipeGestureRecognizerDirectionLeft) {
          NSLog(@"向左轻扫");
      }
      if (gesture.direction == UISwipeGestureRecognizerDirectionDown) {
          NSLog(@"向下轻扫");
      }
      if (gesture.direction == UISwipeGestureRecognizerDirectionUp) {
          NSLog(@"向上轻扫");
      }
  }

  UILongPressGestureRecognizer   长按

      UILongPressGestureRecognizer *longPress=[[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(handleLongPress:)];
      longPress.minimumPressDuration=1;  //至少按下多少秒会触发手势
      longPress.allowableMovement=1;  //允许手指移动的最大距离
      longPress.numberOfTouchesRequired=1; //允许用户用几根手指触发该手势
  
      [_viewText addGestureRecognizer:longPress];

  使用长按手势来显示自定义菜单项

      UIMenuItem *transmItem = [[UIMenuItem alloc]initWithTitle:@"转发" action:@selector(transmItem:)];
      UIMenuItem *deleteItem = [[UIMenuItem alloc]initWithTitle:@"删除" action:@selector(deleteItem:)];
      UIMenuItem *reportItem = [[UIMenuItem alloc]initWithTitle:@"举报" action:@selector(reportItem:)];

  -(void)handleLongPress:(UILongPressGestureRecognizer *)gesture
  {
      if (gesture.state == UIGestureRecognizerStateBegan) {
          NSLog(@"长按手势");
          [self becomeFirstResponder];
          UIMenuController *menu=[UIMenuController sharedMenuController];
          [email protected][transmItem,deleteItem,reportItem];
          CGRect rect=CGRectMake(10, 10, 100, 50);
          [menu setTargetRect:rect inView:_viewText];
          [menu setMenuVisible:YES animated:YES];
      }
  
  }
  -(BOOL)canBecomeFirstResponder
  {
      return YES;
  }
  -(BOOL)canPerformAction:(SEL)action withSender:(id)sender
  {
      if (action == @selector(transmItem:)||action == @selector(deleteItem:)||action == @selector(reportItem:))
      {return YES;}else{
          return NO;}
  }

  -(void)transmItem:(id)sender
  {
      NSLog(@"转发");
  }
  -(void)deleteItem:(id)sender
  {
      NSLog(@"删除");
  }
  -(void)reportItem:(id)sender
  {
      NSLog(@"转发");
  }

如果要是控件同时支持两个手势，需要导入

#import <UIKit/UIGestureRecognizerSubclass.h>

并且，重写两个方法

//是否阻止另一个手势
-(BOOL)canBePreventedByGestureRecognizer:(UIGestureRecognizer *)geature{
    return NO;
}
-(BOOL)canPreventGestureRecognizer:(UIGestureRecognizer *)preventedGestureRecognizer
{
    return NO;
}