自动布局iOS 7 – 无法将子视图右侧的UIScrollView右对齐

我以编程方式构建视图并使用autolayout,没有任何界面构建器.在一个自定义的ScrollView控件中,我添加了一个UILabel和一个UIButton作为子视图.我想将标签对准屏幕左侧,屏幕右侧的按钮.由于某些原因,我的按钮只对齐在我的滚动视图的左边.我已经削减了我的代码,所以只有这两个标签,我不明白为什么它不会对准.

HWScrollViewController.m(如何初始化主滚动视图)

- (void)loadView
{
    self.scrollView = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];

    self.scrollView.delegate = self;

    self.view = self.scrollView;
}

HWListingDetailViewController.m

- (void)viewDidLoad
{
[super viewDidLoad];

UILabel *priceLabel = [[UILabel alloc] init];
UIButton *favouriteButton = [UIButton buttonWithType:UIButtonTypeContactAdd];

[priceLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
[favouriteButton setTranslatesAutoresizingMaskIntoConstraints:NO];

[priceLabel setText:@"$125.00"];
[favouriteButton setTitle:@"Add to Favourites" forState:UIControlStatenormal];

[self.view addSubview:priceLabel];
[self.view addSubview:favouriteButton];

[self.view addConstraints:@[
    [NSLayoutConstraint constraintWithItem:priceLabel 
                                 attribute:NSLayoutAttributeCenterY
                                 relatedBy:NSLayoutRelationEqual 
                                    toItem:self.view 
                                 attribute:NSLayoutAttributeCenterY 
                                multiplier:1 
                                  constant:0],[NSLayoutConstraint constraintWithItem:priceLabel 
                                 attribute:NSLayoutAttributeLeft 
                                 relatedBy:NSLayoutRelationEqual 
                                    toItem:self.view 
                                 attribute:NSLayoutAttributeLeft 
                                multiplier:1 
                                 constant:5],[NSLayoutConstraint constraintWithItem:favouriteButton 
                                 attribute:NSLayoutAttributeCenterY 
                                 relatedBy:NSLayoutRelationEqual 
                                    toItem:self.view 
                                 attribute:NSLayoutAttributeCenterY 
                                multiplier:1 
                                  constant:0],[NSLayoutConstraint constraintWithItem:favouriteButton 
                                 attribute:NSLayoutAttributeRight 
                                 relatedBy:NSLayoutRelationEqual 
                                    toItem:self.view 
                                 attribute:NSLayoutAttributeRight 
                                multiplier:1 
                                  constant:5],

}

您可以看到,绿色价格标签正确对齐,但红色按钮离开屏幕左侧. (我给它5像素的偏移量来显示它的位置.)那么,为什么scrollview的右边实际上是左边的？如何正确对齐屏幕右侧？我哪里做错了？这让我疯狂！

感谢任何帮助！

最终布局图片：
我希望最终的布局是这样的：

如果旋转到景观,我会期待它看起来像这样：

- UIView                                            (self.view)
  - UIScrollView                                    (scrollView)
    - UIView                                        (contentView)
      - UIImageView,UIButtons,UILabels,etc.