ipad - uiscrollbar 不滚动

Question

我为横向视图实现了一个滚动条：

//Add scrollview
    scrollview=[[UIScrollView alloc]initWithFrame:CGRectMake(0,0,1024,768)];
    scrollview.delegate = self;
    scrollview.showsVerticalScrollIndicator=YES;
    scrollview.scrollEnabled=YES;
    scrollview.userInteractionEnabled=YES;
    scrollview.contentOffset = CGPointMake(0, 0);
    scrollview.contentSize = CGSizeMake(1024,2000);
    [self.view addSubview:scrollview];

// 将子视图添加到滚动视图

[self generateSubtaskElements:allObjects];

我试图更改 contentSize，但没有任何反应。我无法欣赏美景。