如果按下子视图按钮,如何取消UIGestureRecognizer

Question

我正在努力从手势识别器中获取我想要的行为,特别是如果其他人已经解雇则取消某些手势.

我有一个scrollView设置为分页和每个页面中的多个子视图.如果用户点击页面的右侧或左侧,我已添加了触摸手势识别器以滚动到下一页或上一页.

    // Add a gesture recogniser turn pages on a single tap at the edge of a page
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGestureHandler:)];
    tapGesture.cancelsTouchesInView = NO;
    [self addGestureRecognizer:tapGesture];
    [tapGesture release];

和我的手势处理程序:

- (void) tapGestureHandler:(UIGestureRecognizer *) gestureRecognizer {
    const CGFloat kTapMargin = 180;

    // Get the position of the point tapped in the window co-ordinate system
    CGPoint tapPoint = [gestureRecognizer locationInView:nil];

    // If the tap point is to the left of the page then go back a page
    if (tapPoint.x > (self.frame.size.width - kTapMargin)) [self scrollRectToVisible:pageViewRightFrame animated:YES];

    // If the tap point is to the right of the page then go forward a page
    else if (tapPoint.x < kTapMargin) [self scrollRectToVisible:pageViewLeftFrame animated:YES];
}

一切都很好,除了我在页面上有子视图的地方有按钮.如果用户触摸subView上的按钮,我希望能够忽略点击以翻页,我无法弄清楚如何执行此操作.

干杯

戴夫

Answer 1

最终对我来说最好的解决方案是使用hitTest来确定点按手势位置下方是否有任何按钮.如果有,则忽略其余的手势代码.

似乎运作良好.想知道我所做的事情是否有任何问题.

- (void) tapGestureHandler:(UIGestureRecognizer *) gestureRecognizer {
    const CGFloat kTapMargin = 180;

    // Get the position of the point tapped in the window co-ordinate system
    CGPoint tapPoint = [gestureRecognizer locationInView:nil];

    // If there are no buttons beneath this tap then move to the next page if near the page edge
    UIView *viewAtBottomOfHeirachy = [self.window hitTest:tapPoint withEvent:nil];
    if (![viewAtBottomOfHeirachy isKindOfClass:[UIButton class]]) {

        // If the tap point is to the left of the page then go back a page
        if (tapPoint.x > (self.bounds.size.width - kTapMargin)) [self scrollRectToVisible:pageViewRightFrame animated:YES];

        // If the tap point is to the right of the page then go forward a page
        else if (tapPoint.x < kTapMargin) [self scrollRectToVisible:pageViewLeftFrame animated:YES];
    }   
}

Answer 2

Apple文档显示了答案:

- (void)viewDidLoad {
      [super viewDidLoad];
      // Add the delegate to the tap gesture recognizer
      self.tapGestureRecognizer.delegate = self;
}

// Implement the UIGestureRecognizerDelegate method
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:    (UITouch *)touch {
      // Determine if the touch is inside the custom subview
     if ([touch view] == self.customSubview){
         // If it is, prevent all of the delegate's gesture recognizers
         // from receiving the touch
        return NO;
     }
     return YES;
}

当然在这种情况下,customSubview将是包含按钮的页面上的子视图(甚至是其上的按钮)