ios - UILabel 在 iOS7 中有一个奇怪的灰色顶线/边框，我该如何删除它？

Question

我有一个在 UITableViewCell 中使用的基本 UILabel。我遇到了一些奇怪的行为，在某些单元格(不是全部)上，UILabel 的顶部边框是灰色的，请参见下图。而且我不确定如何解决它。

我这样创建我的 UILabel:

if (self.postText == nil) {
    CGRect postTextRect = CGRectMake(self.profileImage.frame.origin.x + self.profileImage.frame.size.width + 5, self.username.frame.origin.y + self.username.frame.size.height, frame.size.width - self.profileImage.frame.size.width - self.profileImage.frame.origin.y -10, self.frame.size.height - self.username.frame.size.height - self.username.frame.origin.y + 40);
    self.postText = [[UILabel alloc] initWithFrame:postTextRect];
    self.postText.backgroundColor = [UIColor whiteColor];
    self.postText.textColor = [UIColor darkGrayColor];
    self.postText.userInteractionEnabled = NO;
    self.postText.numberOfLines = 0;
    [self.containerView addSubview:self.postText];
}

关于如何解决这个问题有什么想法吗？

更新

我的 cellForRowAtIndexPath 看起来像这样:

- (id)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    [...]
    static NSString *postCellIdentifier = @"PostCell";
    PostCell *cell = [tableView dequeueReusableCellWithIdentifier:postCellIdentifier];
    if (cell == nil) {
        cell = [[PostCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:postCellIdentifier];
    }

    [self configureCell:cell atIndexPath:indexPath forPost:cellPost];
    return cell;
}

configureCell 的相关部分是这样的:

- (void)configureCell:(PostCell *)cell atIndexPath:(NSIndexPath *)indexPath forPost:(Post *)post
{
    [...]

    cell.username.text = cellUser.username;
    cell.selectionStyle = UITableViewCellSelectionStyleNone;

    CGSize maximumLabelSize = CGSizeMake(cell.postText.frame.size.width, FLT_MAX);
    CGSize expectedLabelSize = [cell.postText.text sizeWithFont:cell.postText.font constrainedToSize:maximumLabelSize lineBreakMode:NSLineBreakByWordWrapping];
    CGRect newFrame = cell.postText.frame;
    newFrame.size.height = expectedLabelSize.height;
    cell.postText.frame = newFrame;

    CGRect containerRect = CGRectMake(5, 5, cell.containerView.frame.size.width, cell.postText.frame.size.height + cell.username.frame.origin.y + cell.username.frame.size.height + 10);
    if (containerRect.size.height < 65) {
        containerRect.size.height = 65;
    }

    cell.containerView.frame = containerRect;
    [...] 
}

Answer 1

我遇到了同样的问题，通过将高度四舍五入解决了这个问题:

newFrame.size.height = ceilf(expectedLabelSize.height);