我将一个空的UIScrollView放入XCode Storyboard,用这段代码给它一个自定义类：

- (id)initWithCoder:(NSCoder *)decoder
{
    self = [super initWithCoder:decoder];
    if (self) {

        int i;
        for (i = 0; i < [self.subviews count]; i++) {
            UIView *view =[self.subviews objectAtIndex:i];
            NSLog(@"sub view %@ x:%f,y:%f,w:%f,h:%f",[view class],view.frame.origin.x,view.frame.origin.y,view.frame.size.width,view.frame.size.height);
        }

    }
    return self;
}

使用空的UIScrollView,这是登录到控制台的内容：

sub view UIImageView x:233.000000,y:121.000000,w:7.000000,h:7.000000
sub view UIImageView x:233.000000,h:7.000000

那些图像是什么？他们放弃了我的计算,因为它们总是低于我的内容.