iPhone模拟器向右滑动可以，但向左滑动不行？

Question

我正在尝试在 UIScrollView 上向左和向右滑动。然而，看起来向左滑动在 iPhone 模拟器中不起作用，尽管向右滑动可以。我错过了什么步骤吗？

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    self.scrollView.multipleTouchEnabled = YES;
    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];
    swipe.delaysTouchesBegan = YES;
    swipe.numberOfTouchesRequired = 2;
    [self.scrollView addGestureRecognizer:swipe];
    [swipe release];
}

- (void)handleSwipe:(UISwipeGestureRecognizer *)recognizer
{
    if (recognizer.direction == UISwipeGestureRecognizerDirectionLeft) {

    } else if (recognizer.direction == UISwipeGestureRecognizerDirectionRight) {

    }
}

Answer 1

使用以下内容：

UISwipeGestureRecognizer *rightRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(rightSwipeHandle:)];
rightRecognizer.direction = UISwipeGestureRecognizerDirectionRight;
[rightRecognizer setNumberOfTouchesRequired:1];
[mainSlideShowImageScrollView addGestureRecognizer:rightRecognizer];
[rightRecognizer release];
UISwipeGestureRecognizer *leftRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(leftSwipeHandle:)];
leftRecognizer.direction = UISwipeGestureRecognizerDirectionLeft;
[leftRecognizer setNumberOfTouchesRequired:1];
[mainSlideShowImageScrollView addGestureRecognizer:leftRecognizer];
[leftRecognizer release];   



- (void)rightSwipeHandle:(UISwipeGestureRecognizer*)gestureRecognizer 
   {
      //Do moving
   }

- (void)leftSwipeHandle:(UISwipeGestureRecognizer*)gestureRecognizer 
{
  // do moving
}

Answer 2

您的“handleSwipe”代码实际上是正确的。您需要两个 UISwipeGestureRecognizer，但您可以将它们都指向同一处理程序，其中包含“IF”语句。

Answer 3

您可以创建一个手势识别器来处理左右滑动（甚至所有方向 -！）：

    UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)];
        swipeGesture.direction = UISwipeGestureRecognizerDirectionLeft | UISwipeGestureRecognizerDirectionRight;

所有方向：

  swipeGesture.direction = UISwipeGestureRecognizerDirectionLeft | UISwipeGestureRecognizerDirectionRight | UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionDown;