Question

我正在尝试在UITableview中创建一个包含3个标签的节标题，其布局看起来有点像这样

-------------------------------
| title              | dist   |
|                             |
| Description                 |
|                             |
-------------------------------

Title和time都是固定大小，但description需要根据内容自动调整其高度，最小高度为单行文字。

我当前的标题结构由

组成

UIView
|_ UIView
      |_ UILabel
      |_ UILabel
      |_ UILabel

外部UIView是节标题本身，背景清晰，内部UIView是带标签的可见视图。

我所追求的是，节标题根据描述标签中的内容调整其高度。

我已尝试实施tableView:heightForHeaderInSection:，但似乎没有效果。 iOS抱怨我必须打破限制，我认为这是有意义的，因为我设置了约束，但是然后用这种方法手动覆盖它们？

如何创建允许视图调整自身大小的约束？现在，我有viewForHeaderInSection:

的以下实现

- (UIView *) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    if (section == 0) {
        UIView *header = [UIView new];
        UIView *headerBg = [UIView new];
        UILabel *title = [UILabel new];
        UILabel *distance = [UILabel new];
        UILabel *desc = [UILabel new];

        headerBg.translatesAutoresizingMaskIntoConstraints = NO;
        title.translatesAutoresizingMaskIntoConstraints = NO;
        distance.translatesAutoresizingMaskIntoConstraints = NO;
        desc.translatesAutoresizingMaskIntoConstraints = NO;

        [headerBg setBackgroundColor:[UIColor colorWithWhite:1.0 alpha:0.8]];

        [title setFont:[UIFont fontWithName:@"HelveticaNeue-Bold" size:14.0]];
        [title setTextColor:kFONT_COLOUR];
        NSString *address = _place.address ? (_place.address.length > 0 ? _place.address : @"Unknown Address") : @"Unknown Address";
        [title setText:address];

        [distance setFont:[UIFont fontWithName:@"HelveticaNeue" size:14.0]];
        [distance setTextColor:kFONT_COLOUR];
        [distance setText:@"Distance: ?m"];
        [distance setTextAlignment:NSTextAlignmentRight];

        [desc setFont:[UIFont fontWithName:@"HelveticaNeue" size:11.0]];
        [desc setTextColor:kFONT_COLOUR];
        [desc setNumberOfLines:0];
        [desc setLineBreakMode:NSLineBreakByWordWrapping];
        [desc setText:_place.desc ? (_place.desc.length > 0 ? _place.desc : @"No Description Given") : @"No Description Given"];

        [headerBg addSubview:title];
        [headerBg addSubview:distance];
        [headerBg addSubview:desc];

        NSDictionary *bindings = NSDictionaryOfVariableBindings(title, distance, desc, headerBg);

        [headerBg addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|-9-[title]-[distance(100)]-9-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:bindings]];
        [headerBg addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|-9-[desc]-9-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:bindings]];
        [headerBg addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-9-[title(20)]-[desc]-|" options:NSLayoutFormatAlignAllLeading metrics:nil views:bindings]];

        [header addSubview:headerBg];
        [header addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|[headerBg]|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:bindings]];
        [header addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[headerBg]-9-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:bindings]];
        return header;
    }

    return nil;
}

任何帮助都会很棒：）

UIView高度基于Autolayout的内容

0 个答案: