iPhone:向滚动视图添加按钮使按钮无法交互

问题描述

由于某种原因，在我的 viewController 的 addBook 方法中初始化的按钮不会响应触摸.我分配给它的选择器永远不会触发，UIControlStateHighlighted 图像也不会在点击图像时出现.

For some reason, the button initialized in the addBook method of my viewController won't respond to touches. The selector I've assigned to it never triggers, nor does the UIControlStateHighlighted image ever appear when tapping on the image.

在触摸到 UIButton 之前是否有任何东西拦截了触摸，或者它的交互性是否被我正在做的事情以某种方式禁用?

- (void)viewDidLoad {

    ...

    _scrollView.contentSize = CGSizeMake(currentPageSize.width, currentPageSize.height);
    _scrollView.showsHorizontalScrollIndicator = NO;
    _scrollView.showsVerticalScrollIndicator = NO;
    _scrollView.scrollsToTop = NO;
    _scrollView.pagingEnabled = YES;

    ...
}

- (void)addBook {
    // Make a view to anchor the UIButton
    CGRect frame = CGRectMake(0, 0, currentPageSize.width, currentPageSize.height);
    UIImageView* bookView = [[UIImageView alloc] initWithFrame:frame];

    // Make the button
    frame = CGRectMake(100, 50, 184, 157);
    UIButton* button = [[UIButton alloc] initWithFrame:frame];
    UIImage* bookImage = [UIImage imageNamed:kBookImage0];

    // THIS SECTION NOT WORKING!
    [button setBackgroundImage:bookImage forState:UIControlStateNormal];
    UIImage* bookHighlight = [UIImage imageNamed:kBookImage1];
    [button setBackgroundImage:bookHighlight forState:UIControlStateHighlighted];
    [button addTarget:self action:@selector(removeBook) forControlEvents:UIControlEventTouchUpInside];

    [bookView addSubview:button];   
    [button release];
    [bookView autorelease];

    // Add the new view/button combo to the scrollview.
    // THIS WORKS VISUALLY, BUT THE BUTTON IS UNRESPONSIVE :(
    [_scrollView addSubview:bookView];
}

- (void)removeBook {
    NSLog(@"in removeBook");
}

Interface Builder 中的视图层次结构如下所示:

The view hierarchy looks like this in Interface Builder:

UIWindow
UINavigationController
    RootViewController
        UIView
            UIScrollView
            UIPageControl

一旦 addBook 方法运行，大概就是这样:

and presumably like this once the addBook method runs:

UIWindow
UINavigationController
    RootViewController
        UIView
            UIScrollView
                UIView
                    UIButton
            UIPageControl

推荐答案

UIScrollView 可能正在捕获所有的触摸事件.

THe UIScrollView might be catching all the touch events.

也许可以尝试以下组合:

Maybe try a combination of the following:

_scrollView.delaysContentTouches = NO;
_scrollView.canCancelContentTouches = NO;

和

bookView.userInteractionEnabled = YES;