ios - sizewithAttributes 没有为 uilabels 返回正确的高度

Question

我正在尝试使用 sizewithattributes 方法计算 uitableview 中 uilabels 的正确高度。但是它返回的高度远低于应有的高度，标签文本被截断并且从 textwithattributes 返回的高度输出到控制台显示高度约为 20 - 40，即使对于完整的文本段落也是如此。我已经将我的字体大小和字体设置为与该方法的属性部分中的 uilabel 相同，并且我将 uilabel 的换行模式设置为 wordwrap。提前致谢

代码:`

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(  NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    NSDictionary *message =  self.messages[indexPath.row];
    NSLog(@"%lu", (long)indexPath.row);
    UILabel *nameLabel = (UILabel *)[cell.contentView viewWithTag:20000];
    UILabel *messageContent = (UILabel *)[cell.contentView viewWithTag:10000];
    UIImageView *image = (UIImageView *)[cell.contentView viewWithTag:30000];
    UIButton *replyButton = (UIButton *)[cell.contentView viewWithTag:40000];
    replyButton.tag = indexPath.row;
    messageContent.text = [message objectForKey:@"messageContent"];
    NSString *content = [message objectForKey:@"messageContent"];
    NSLog(@"Message: %@", content);

    NSDictionary *attributes = @{NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue" size:17.0f]};
    // NSString class method: boundingRectWithSize:options:attributes:context is
    // available only on ios7.0 sdk.
    CGRect rect = [content boundingRectWithSize:CGSizeMake(10000, MAXFLOAT)
                                              options:NSStringDrawingUsesLineFragmentOrigin
                                           attributes:attributes
                                              context:nil];

    CGFloat height = ceilf(rect.size.height);
    CGFloat width  = ceilf(rect.size.width);
    messageContent.frame = CGRectMake(40, 126, width, height);


    NSLog(@"Height:%f", messageContent.frame.size.height);
    NSLog(@"y: %f", messageContent.frame.origin.y);
    NSLog(@"estimated height: %f", height);




    nameLabel.text = [message objectForKey:@"senderName"];

    UIImage *senderPic = self.senderPictures[indexPath.row];
    image.image = senderPic;
    image.layer.cornerRadius = 27.0;
    image.layer.masksToBounds = YES;





    return cell;
}
`

Answer 1

你的问题是:

//[content boundingRectWithSize:CGSizeMake(10000, MAXFLOAT)

您指定 100000 pt 作为文本宽度，我不知道您的 content 字符串包含多少个字符，但我相信您可以轻松地在一两行中显示它，如果您的行长 10000 pt。

更好的方法是将文本添加到它的标签读取大小，并根据需要更改标签框架:

CGSize labelSize = [self.messageContent.text sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:self.messageContent.font.pointSize]}];