uiScrollView底部的uiButtons未接收到触摸

我正在编写一个带有标签栏和导航栏的iPhone应用程序。在某个时刻,我将detailsViewController类的一个实例推到导航控制器堆栈上以显示它。

此控制器在代码中创建其视图层次结构:控制器的 view 属性设置为uiScrollView,它包含一个普通的uiView(我们称之为“ContentView”),其大小可容纳要显示的所有内容。在这个ContentView的底部,我有四个ui按钮。

现在,当我运行应用程序(目前在模拟器中)并滚动到视图的底部时,顶部的两个按钮响应触摸;第三个按钮只响应顶部的触摸,而下部的按钮根本不响应触摸。通过单击第三个按钮的各个部分,滚动视图中较低的93个像素似乎不会将触摸事件传递给其子视图。

93是可疑的:它也是标签栏(49像素)和导航栏(44像素)的组合高度。但是导航栏和选项卡栏在滚动视图之外。有什么建议为什么会这样吗?

下面是有问题的代码:

- (void)loadView
{
    CGRect frame = [[UIScreen mainScreen] applicationFrame]; 
    UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:frame];
    scrollView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
    scrollView.delegate = self;
    self.view = scrollView;

    UIView *contentView = [[UIView alloc] initWithFrame:scrollView.bounds];
    contentView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
    [scrollView addSubview:contentView];

    CGSize viewSize = contentView.bounds.size;
    CGSize size;
    CGFloat y = 0;

    /* Snip creating various labels and image views */

    /* Actions view creates and lays out the four buttons; its sizeThatFits:
    ** method returns the frame size to contain the buttons */

    actionsView = [[PropertyDetailActionsView alloc] initWithFrame:CGRectZero];
    actionsView.autoresizingMask = (UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleWidth);
    actionsView.delegate = self;
    size = [actionsView sizeThatFits:viewSize];
    actionsView.frame = CGRectMake(0, y, size.width, size.height);
    [contentView addSubview:actionsView];
    y += size.height;

    [contentView setFrame:CGRectMake(0, 0, viewSize.width, y)];
    scrollView.contentSize = contentView.frame.size;

    [contentView release];
    [scrollView release];
}