当将UIScrollView添加为子视图时，UIButtons不会滚动

Question

我试图构建一个简单的UIScrollView，分页到3个图像之间水平滚动。棘手的部分是，我希望每个图像将是可点击和捕捉点击事件。

我的技术是创建3个UIButtons，每个UIImage由UIImage组成。给每个按钮一个标签并设置一个动作。

问题:我可以捕捉点击事件-但它是不可滚动的！

这是我的代码：

- (void) viewDidAppear:(BOOL)animated {

    _imageArray = [[NSArray alloc] initWithObjects:@"content_01.png", @"content_02.png", @"content_03.png", nil];

    for (int i = 0; i < [_imageArray count]; i++) {
        //We'll create an imageView object in every 'page' of our scrollView.
        CGRect frame;
        frame.origin.x = _contentScrollView.frame.size.width * i;
        frame.origin.y = 0;
        frame.size = _contentScrollView.frame.size;

        //
        //get the image to use, however you want
        UIImage* image = [UIImage imageNamed:[_imageArray objectAtIndex:i]];

        UIButton* button = [[UIButton alloc] initWithFrame:frame];

        //set the button states you want the image to show up for
        [button setImage:image forState:UIControlStateNormal];
        [button setImage:image forState:UIControlStateHighlighted];

        //create the touch event target, i am calling the 'productImagePressed' method
        [button addTarget:self action:@selector(imagePressed:)
         forControlEvents:UIControlEventTouchUpInside];
        //i set the tag to the image #, i was looking though an array of them
        button.tag = i;

        [_contentScrollView addSubview:button];
    }

    //Set the content size of our scrollview according to the total width of our imageView objects.
    _contentScrollView.contentSize = CGSizeMake(_contentScrollView.frame.size.width * [_imageArray count], _contentScrollView.frame.size.height);

    _contentScrollView.backgroundColor = [ENGAppDelegate backgroundColor];
    _contentScrollView.delegate = self;
}

Answer 1

因为UIButton是一个UIControl子类，所以它“吞噬”了滚动视图的触感：

[UIScrollView touchesShouldCancelInContentView:]如果视图不是UIControl对象，则默认返回值为YES；否则，它将返回NO。

(来自ref/occ/instm/UIScrollView/touchesShouldCancelInContentView:)

您可以通过子类UIScrollView和覆盖touchesShouldCancelInContentView: (和/或touchesShouldBegin:withEvent:inContentView:)来影响这一点。但是，对于您的用例，我首先不会使用按钮。为什么不添加一个点击手势识别器到滚动视图，并使用触摸点，以确定哪个图像已被点击？这要容易得多，而且应该没有任何问题。

Answer 2

这完全解决了这个问题：

scrollview.panGestureRecognizer.delaysTouchesBegan = YES;

https://stackoverflow.com/users/904365/kjuly在本主题中提供了正确的答案：ScrollView/TableView with UIControl/UIButton subviews not scrollable under iOS 8