UIScrollView具有自动布局

Question

我有一个对象数组并在滚动视图中显示它们。如果用户在该数组中添加或删除模型，我想重新加载滚动视图。

我正在使用iOS6发行说明中描述的混合方法

- (void)layoutScrollView
{
    [self clearScrollView]; // loop through scroll view's subviews and call remove from super view

int contentHeight = (BANQUET_TICKET_HEIGHT * self.banquetList.count) + ADD_BUTTON_HEIGHT + 60;
UIView *containerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 300, contentHeight)];
containerView.backgroundColor = [UIColor blueColor];
[self.scrollView setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.scrollView addSubview:containerView];
[self.scrollView setContentSize:CGSizeMake(300, contentHeight)];

CGFloat originY = 0;
for (int i = 0; i < self.banquetList.count; i ++) // add tickets
{
    UIView *ticket = [[UIView alloc] init];
    [containerView addSubview:ticket];
    [ticket setTranslatesAutoresizingMaskIntoConstraints:NO];
    NSLayoutConstraint *width = [NSLayoutConstraint constraintWithItem:ticket
                                                             attribute:NSLayoutAttributeWidth
                                                             relatedBy:NSLayoutRelationEqual
                                                                toItem:nil
                                                             attribute:NSLayoutAttributeWidth
                                                            multiplier:1
                                                              constant:BANQUET_TICKET_WIDTH];
    NSLayoutConstraint *height = [NSLayoutConstraint constraintWithItem:ticket
                                                              attribute:NSLayoutAttributeHeight
                                                              relatedBy:NSLayoutRelationEqual
                                                                 toItem:nil
                                                              attribute:NSLayoutAttributeHeight
                                                             multiplier:1
                                                               constant:BANQUET_TICKET_HEIGHT];
    [ticket addConstraints:@[width, height]];

    NSLayoutConstraint *leading = [NSLayoutConstraint constraintWithItem:ticket
                                                               attribute:NSLayoutAttributeLeading
                                                               relatedBy:NSLayoutRelationEqual
                                                                  toItem:containerView
                                                               attribute:NSLayoutAttributeLeading
                                                              multiplier:1
                                                                constant:0];
    NSLayoutConstraint *top = [NSLayoutConstraint constraintWithItem:ticket
                                                           attribute:NSLayoutAttributeTop
                                                           relatedBy:NSLayoutRelationEqual
                                                              toItem:containerView
                                                           attribute:NSLayoutAttributeTop
                                                          multiplier:1
                                                            constant:originY];
    [containerView addConstraints:@[leading, top]];
    originY += 150;

}
if ([containerView hasAmbiguousLayout])
{
    [containerView exerciseAmbiguityInLayout];
    NSLog(@"hasAmbiguousLayout");
}
}

它只在我第一次在viewDidLoad中调用此方法时才有效。但是，如果我修改数组并再次调用此方法，hasAmbiguousLayout将返回YES。它不会崩溃应用程序，故障单视图显示，但滚动视图将无法正确滚动，它无法滚动到最顶部或最底部的内容，只显示其内容的一部分。像内容大小的内容已经改变了。

实现这一目标的正确方法是什么？有人可以帮帮我吗？

感谢。