iphone - 将 UIButton 添加到 UIScrollView，然后将 UIScrollView 添加到 UIView

Question

我需要以编程方式创建一个 UIButton，然后将其放在创建的 UIScrollView 上，然后将 UIScrollView 放在 UIView 上。如果将这些元素添加到 self.view 它们会显示，但是当我想嵌套时它们不会显示。 这是我目前所拥有的:

viewWithPictures=[[UIScrollView alloc] initWithFrame:self.bottomView.frame];
viewWithPictures.contentSize=CGSizeMake(160*[smallImagesFromGallery count], self.bottomView.frame.size.height);

viewWithPictures.backgroundColor=[UIColor greenColor];
NSLog(@"Number of small images: %i",[smallImagesFromGallery count]); 

for(int i=0; i<[smallImagesFromGallery count]; i++)
{
    UIButton *btn=[UIButton buttonWithType:UIButtonTypeCustom];

    btn.frame=CGRectMake(self.bottomView.frame.origin.x+i*160, self.bottomView.frame.origin.y, 150, 100);

    [btn setBackgroundImage:[smallImagesFromGallery objectAtIndex:i] forState:UIControlStateNormal];
    if (btn==nil) {
        NSLog(@"Button is nil");
    }
    btn.tag=i;
    [btn addTarget:self action:@selector(viewLargeVersion:) forControlEvents:UIControlEventTouchUpInside];
    [viewWithPictures addSubview:btn];



}
[bottomView addSubview:viewWithPictures];

Answer 1

当您设置将成为 subview 的 View 的框架时，您需要引用它将添加到的 View 的边界。所以我认为您需要更改几行:

viewWithPictures=[[UIScrollView alloc] initWithFrame:self.bottomView.frame];

应该是:

viewWithPictures=[[UIScrollView alloc] initWithFrame:self.bottomView.bounds];

和

btn.frame=CGRectMake(self.bottomView.frame.origin.x+i*160, self.bottomView.frame.origin.y, 150, 100);

应该是:

btn.frame=CGRectMake(i*160, 0, 150, 100);