在UIScrollView子视图中的UILabels上的UITapGestureRecognizer无法正常工作

Question

我的UIScrollView内容视图中的UILabels上的UITapGestureRecognizer没有调用它的方法.

视图层次结构如下:

• scrollView(UIScrollView)
  • contentView(UIView)
    • testLabel(UILabel) - 这里是附加UITapGestureRecognizer的地方

我已经将代码简化为一个示例以突出显示该问题

// Set scrollview size - Added in Storyboad
[scrollView setContentSize:CGSizeMake([arrayOfVerbs count]*self.view.frame.size.width, scrollView.contentSize.height)];
[scrollView setCanCancelContentTouches:YES]; // Tried both yes and no
[scrollView setPagingEnabled:YES];

// Add content view
UIView *contentView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, scrollView.contentSize.width, scrollView.contentSize.height)];
[scrollView addSubview:contentView];

// Add test UILabel
UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 200, 100)];
[testLabel setBackgroundColor:[UIColor redColor]];
[testLabel setText:@"Test touch"];
[testLabel setUserInteractionEnabled:YES];
[contentView addSubview:testLabel];

// Add gesture recogniser
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(playSound:)];
singleTap.numberOfTapsRequired = 1;
[testLabel addGestureRecognizer:singleTap];

这是点击手势识别器应该调用的方法

- (void)playSound:(UITapGestureRecognizer *)sender {

    NSLog(@"play sound");

    if(sender.state == UIGestureRecognizerStateEnded)
    {
        int pronounNumber = [sender.view tag];
        int exampleNumber = (int)sender.view.frame.origin.x%(int)self.view.frame.size.width;

        NSLog(@"Pronoun is %i and example is %i", pronounNumber, exampleNumber);
    }
}

当我试图触摸UILabel时,从不调用此方法.

我已经尝试将属性canCancelContentTouches设置为滚动视图上的YES和NO,如此线程所示,但它仍然无法正常工作.

奇怪的是,如果我在scrollView之外添加一个UILabel,那么手势识别器就可以了!所以问题只出现在我的contentView中,它是我的scrollView的子视图.

我正在使用自动布局,如果这可能有任何区别？

谢谢!

Answer 1

滚动视图还具有手势识别器.默认情况下,任何时候只有一个手势识别器可以处理触摸.你需要让自己成为你的手势的代表,然后实现gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:返回YES.这将允许它与滚动视图同时工作.