ios - 由于设置了 UIPanGestureRecognizer，未调用 UISwipeGestureRecognizer @selector

Question

在我的 iOS 应用程序中，我进行了以下设置:

- (void)setupGestures
{
   UIPanGestureRecognizer* panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];                                                           
   [self.view addGestureRecognizer:panRecognizer];

   UISwipeGestureRecognizer* swipeUpRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];

   [swipeUpRecognizer setDirection:UISwipeGestureRecognizerDirectionUp];
   [self.view addGestureRecognizer:swipeUpRecognizer];
}

// then I have following implementation of selectors

// this method supposed to give me the length of the swipe

- (void)panGesture:(UIPanGestureRecognizer *)sender 
{
   if (sender.state == UIGestureRecognizerStateBegan)
   {
      startLocation = [sender locationInView:self.view];
   }
   else if (sender.state == UIGestureRecognizerStateEnded)
   {
      CGPoint stopLocation = [sender locationInView:self.view];
      CGFloat dx = stopLocation.x - startLocation.x;
      CGFloat dy = stopLocation.y - startLocation.y;
      CGFloat distance = sqrt(dx*dx + dy*dy );
      NSLog(@"Distance: %f", distance);
   }
 }

 // this  method does all other actions related to swipes

- (void)handleSwipe:(UISwipeGestureRecognizer *)gestureRecognizer
{
 UISwipeGestureRecognizerDirection direction = [gestureRecognizer direction];
     CGPoint touchLocation = [gestureRecognizer locationInView:playerLayerView];

     if (direction == UISwipeGestureRecognizerDirectionDown && touchLocation.y >  (playerLayerView.frame.size.height * .5))
     {
        if (![toolbar isHidden])
        {
           if (selectedSegmentIndex != UISegmentedControlNoSegment)
           {
              [self dismissBottomPanel];
           }
           else
           {
             [self dismissToolbar];
           }
        }
     }
 }

所以问题是 handleSwipe 永远不会被调用...当我注释掉 UIPanGestureRecognizer 设置时，handleSwipe 开始工作。

我对手势识别编程还很陌生，所以我假设我在这里遗漏了一些基本知识。

非常感谢任何形式的帮助!

Answer 1

您需要告诉手势如何相互交互。这可以通过让它们同时运行(默认情况下它们不会运行)或将一个设置为仅在另一个失败时才运行来实现。

为了让它们都起作用，让你的类成为手势的委托(delegate)并实现

– gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:

返回YES。

要将一个设置为仅在另一个失败时才工作，请使用 requireGestureRecognizerToFail:。