ios - UIScrollView 中的 UIView 没有出现

Question

我正在尝试创建一个类似于 this video 中的水平滚动菜单.

由于某些原因，UIView 在向其添加一堆 UIButtons 并将其添加到 UIScrollView 后没有出现。这是我的代码(在 UIViewController 的子类的 -viewDidLoad 中调用):

//set up scrollview
UIScrollView *designPicker = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 431, 320, 49)];

//set up a view to drop into the scroll view
UIView * buttonsView = [[UIView alloc] initWithFrame:CGRectMake(0, 431, 640, 49)];

//add buttons to scrollview
// load all the images from our bundle and add them to the scroll view
NSUInteger i;
float runningX = designPicker.frame.origin.x;
for (i = 1; i <= 10; i++)
{
    UIButton *tempBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    [tempBtn setBackgroundImage:[UIImage imageNamed:@"button.png"] forState:UIControlStateNormal];
    CGRect rect = CGRectMake(runningX, designPicker.frame.origin.y, 30.0, 30.0);
    tempBtn.frame = rect;
    [buttonsView addSubview:tempBtn];
    runningX = runningX + 35;
    [tempBtn release];
}

[designPicker setContentSize:buttonsView.frame.size];
[designPicker addSubview:buttonsView];
[self.view addSubview:designPicker];

Answer 1

您不应使用 UIScrollView 的框架添加按钮。框架的原点位于父 View (UIScrollView 的父 View )坐标中。您应该使按钮的框架相对于 UIView。因此，如果您希望按钮出现在 View 的顶部，您应该从 (0,0) 开始。