ios - 如何使用 XCode 6 在 iOS 7 的 UItableviewCell 中制作 UIlabel 的动态高度

Question

我正在使用 Xcode 6 并创建了一个新项目并在 iOS7 中遇到自动布局问题，因为它在 iOS8 中正常工作。我正在使用以下代码:-

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"cell";

    UITableViewCell *cell = (UITableViewCell*)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    UILabel *lbl1=(UILabel*)[cell.contentView viewWithTag:1];
    lbl1.text = @"test fkdjsjk kjhsdf ksjh ksjdhf jks kjh kjdhf kjsd h kjh j ,jhfjdfshfk jh fkjsdh fkjs dhkfjhs dkjfh dksjhf jksd hfjkdhs fk jksdhf kjsdh fkjsdh fjkhdsk fjkdsh fkjdsh fkjdsh fkjs djkf djksf kjdshfkjds fkjdsh fkjhs dkjfh kdjs fkdjshfkdsjfh kdjsh fk";


       [lbl1 setPreferredMaxLayoutWidth:lbl1.frame.size.width];




    [cell setNeedsUpdateConstraints];
    [cell updateConstraintsIfNeeded];

    cell.frame = CGRectMake(0.0f, 0.0f, CGRectGetWidth(cell.bounds), CGRectGetHeight(tableView.bounds));

    [cell setNeedsLayout];
    [cell layoutIfNeeded];

    CGFloat height = [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;

    return height;
}
- (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath
{

    static NSString *simpleTableIdentifier = @"cell";
    UITableViewCell *cell = (UITableViewCell*)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];

    return cell.frame.size.height;

}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"cell";

    UITableViewCell *cell = (UITableViewCell*)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
      UILabel *lbl1=(UILabel*)[cell.contentView viewWithTag:1];
     lbl1.text = @"test fkdjsjk kjhsdf ksjh ksjdhf jks kjh kjdhf kjsd h kjh j ,jhfjdfshfk jh fkjsdh fkjs dhkfjhs dkjfh dksjhf jksd hfjkdhs fk jksdhf kjsdh fkjsdh fjkhdsk fjkdsh fkjdsh fkjdsh fkjs djkf djksf kjdshfkjds fkjdsh fkjhs dkjfh kdjs fkdjshfkdsjfh kdjsh fk";

     [lbl1 setBackgroundColor:[UIColor greenColor]];

    [cell.contentView setBackgroundColor:[UIColor redColor]];


    [cell setNeedsUpdateConstraints];
    [cell updateConstraintsIfNeeded];



    return cell;
}

我的要求只是在 iOS 7 中标签应该动态地获取高度作为提供给它的内容。

Answer 1

你需要这样做。

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {

    CGSize constrainedSize = CGSizeMake(self.view.frame.size.width - 30, FLT_MAX);

    NSDictionary *attributesDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                          [UIFont fontWithName:@"HelveticaNeue" size:14], NSFontAttributeName,
                                          nil];

    CGRect requiredHeight = [YourStringObject boundingRectWithSize:constrainedSize
                                                                      options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                                                   attributes:attributesDictionary
                                                                      context:nil];

    return requiredHeight.size.height + 20;
}

我使用额外的 20 作为额外的填充。希望这对你有用。