按下时，UILongPressGestureRecognizer会被调用两次

7 回答

• 18

  您需要检查正确的状态，因为每个州都有不同的行为 . 很可能你需要使用 UILongPressGestureRecognizer 的 UIGestureRecognizerStateBegan 状态 .

  UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]
                                               initWithTarget:self 
                                               action:@selector(handleLongPress:)];
  longPress.minimumPressDuration = 1.0;
  [myView addGestureRecognizer:longPress];
  [longPress release];
  

  ...

  - (void)handleLongPress:(UILongPressGestureRecognizer *)gesture {
      if(UIGestureRecognizerStateBegan == gesture.state) {
          // Called on start of gesture, do work here
      }
  
      if(UIGestureRecognizerStateChanged == gesture.state) {
          // Do repeated work here (repeats continuously) while finger is down
      }
  
      if(UIGestureRecognizerStateEnded == gesture.state) {
          // Do end work here when finger is lifted
      }
  }
  

  回复于 2024-05-08T21:13:08+08:00
• 113

  UILongPressGestureRecognizer是一个连续的事件识别器 . 你必须查看状态，看看这是事件的开始，中间还是结束，并采取相应的行动 . 即你可以在开始后丢弃所有事件，或者只根据需要查看运动 . 来自Class Reference：

  长按手势是连续的 . 当指定时间段（minimumPressDuration）按下允许的手指数（numberOfTouchesRequired）并且触摸不超出允许的移动范围（allowableMovement）时，手势开始（UIGestureRecognizerStateBegan） . 每当手指移动时，手势识别器转换到改变状态，并且当任何手指被抬起时，手势识别器结束（UIGestureRecognizerStateEnded） .

  现在你可以追踪像这样的状态

  -  (void)handleLongPress:(UILongPressGestureRecognizer*)sender { 
      if (sender.state == UIGestureRecognizerStateEnded) {
        NSLog(@"UIGestureRecognizerStateEnded");
      //Do Whatever You want on End of Gesture
       }
      else if (sender.state == UIGestureRecognizerStateBegan){
         NSLog(@"UIGestureRecognizerStateBegan.");
     //Do Whatever You want on Began of Gesture
       }
    }
  

  回复于 2024-05-08T21:13:08+08:00
• 5

  要检查UILongPressGestureRecognizer的状态，只需在选择器方法上添加if语句：

  - (void)handleLongPress:(UILongPressGestureRecognizer *)sender {    
      if (sender.state == UIGestureRecognizerStateEnded) {
          NSLog(@"Long press Ended");
      } else if (sender.state == UIGestureRecognizerStateBegan) {
          NSLog(@"Long press detected.");
      }
  }
  

  回复于 2024-05-08T21:13:08+08:00
• 12

  试试这个：

  Objective-C

  - (void)handleLongPress:(UILongPressGestureRecognizer*)sender { 
      if (sender.state == UIGestureRecognizerStateEnded) {
          NSLog(@"Long press Ended");
      } else if (sender.state == UIGestureRecognizerStateBegan) {
          NSLog(@"Long press detected.");
      }
  }
  

  Swift 2.2:

  func handleLongPress(sender:UILongPressGestureRecognizer) {
  
          if (sender.state == UIGestureRecognizerState.Ended) {
              print("Long press Ended");
          } else if (sender.state == UIGestureRecognizerState.Began) {
              print("Long press detected.");
          }
  }
  

  回复于 2024-05-08T21:13:08+08:00
• 643

  以下是在Swift中处理它的方法：

  func longPress(sender:UILongPressGestureRecognizer!) {
  
          if (sender.state == UIGestureRecognizerState.Ended) {
              println("Long press Ended");
          } else if (sender.state == UIGestureRecognizerState.Began) {
              println("Long press detected.");
          }
  }
  

  回复于 2024-05-08T21:13:08+08:00
• 12

  Swift 3.0：

  func handleLongPress(sender: UILongPressGestureRecognizer) {
  
      if sender.state == .ended {
          print("Long press Ended")
      } else if sender.state == .began {
          print("Long press detected")
      }
  

  回复于 2024-05-08T21:13:08+08:00
• 69

  您的手势处理程序接收每个手势状态的调用 . 所以你需要检查每个状态并将你的代码置于必需的状态 .

  人们必须更喜欢在if-else上使用switch-case：

  UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]
                                           initWithTarget:self 
                                           action:@selector(handleLongPress:)];
      longPress.minimumPressDuration = 1.0;
      [myView addGestureRecognizer:longPress];
      [longPress release];
  

  ---

  -(void)handleLongPress:(UILongPressGestureRecognizer *)gesture {
          switch(gesture.state){
            case UIGestureRecognizerStateBegan:
                 NSLog(@"State Began");
                 break;
            case UIGestureRecognizerStateChanged:
                 NSLog(@"State changed");
                 break;
            case UIGestureRecognizerStateEnded:
                 NSLog(@"State End");
                 break;
            default:
                 break;
           }
  }
  

  回复于 2024-05-08T21:13:08+08:00