iphone - 如果按下 subview 的按钮如何取消 UIGestureRecognizer

Question

我正在努力从手势识别器中获得我想要的行为，特别是在其他手势已触发时取消某些手势。

我有一个 ScrollView 设置为分页和每个页面中的多个 subview 。我添加了一个触摸手势识别器，如果用户点击页面的右侧或左侧，则可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];
}

一切正常，除了页面上有一个包含按钮的 subview 。如果用户触摸 subview 上的按钮，我希望能够忽略翻页的点击，但我不知道如何执行此操作。

干杯

戴夫

Answer 1

最终对我来说最有效的解决方案是使用 hitTest 来确定点击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。

看起来效果不错。想知道我所做的是否有任何问题。

- (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];
    }   
}