Question

我正在使用Masonry pod来控制我在tableView中的UI元素上的约束，我的视图扩展了UITableViewCell。我每个单元格有三个UI元素，显示流行邮轮港口的评级和评论。根据端口是否已被评级，删除并替换其中一个元素。

在一周之前，审查的UILabel显示没有任何额外的填充，但现在它显示在UILabel的顶部和底部似乎有2个额外的填充线。

以下是相关代码：

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
    if (self = [super initWithStyle:style reuseIdentifier:reuseIdentifier]) {
        self.rating = 0;

        //solves autolayout error http://stackoverflow.com/questions/19132908/auto-layout-constraints-issue-on-ios7-in-
//        self.contentView.bounds = CGRectMake(0, 0, 99999, 99999);
        // description label
        self.descriptionLabel = [[UILabel alloc] init];
        [self.descriptionLabel setPreferredMaxLayoutWidth:self.contentView.bounds.size.width];
        [self.descriptionLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
        [self.descriptionLabel setFont:[UIFont fontWithName:[StringFactory defaultFontType] size:14.0f]];
        [self.descriptionLabel setTextColor:[ColorFactory CC333]];
        [self.descriptionLabel setNumberOfLines:0];
        [self.descriptionLabel sizeToFit];
        // Without this, it can happen that the last line of the text to be displayed can be cut, although
        // all the proper constraints seem to be set correctly.
        [self.descriptionLabel setAdjustsFontSizeToFitWidth:NO];
        [self.descriptionLabel setBackgroundColor:[ColorFactory CCOrange]];
        [self.contentView addSubview:self.descriptionLabel];


        // create date label
        self.dateLabel = [[UILabel alloc] init];
        [self.dateLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
        [self.dateLabel setFont:[UIFont fontWithName:[StringFactory defaultFontType] size:14.0f]];
        [self.dateLabel setTextColor:[ColorFactory CC333]];
        [self.contentView addSubview:self.dateLabel];

        //create ratingView
        self.ratingView = [[UIImageView alloc] init];
        [self.ratingView setTranslatesAutoresizingMaskIntoConstraints:NO];
        [self.contentView addSubview:self.ratingView];

        // create ratingLabel
        self.ratingLabel = [[UILabel alloc] init];
        [self.ratingLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
        [self.ratingLabel setFont:[UIFont fontWithName:[StringFactory defaultBoldFontType] size:14.0f]];
        [self.ratingLabel setTextColor:[ColorFactory CC333]];
        [self.contentView addSubview:self.ratingLabel];

        self.contentView.backgroundColor = [UIColor whiteColor];

        // add KVO to update cell
        [self addObserver:self forKeyPath:@"portReview" options:NSKeyValueObservingOptionNew context:nil];

        //Add constraints
        [self setLayout];
    }

    return self;
}

- (void)dealloc {
    [self removeObserver:self forKeyPath:@"portReview" context:nil];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if ([keyPath isEqualToString:@"portReview"]) {
        [self configureCell];
    }
}

- (void)configureCell {
    self.descriptionLabel.text = self.portReview.review;

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setTimeZone: [NSTimeZone timeZoneWithAbbreviation:@"EST"]];
    [dateFormatter setDateFormat:[StringFactory shortDateFormat]];
    NSMutableString *authorString = [NSMutableString stringWithString:@""];
    if (self.portReview.author != nil)
    {
        authorString = [NSMutableString stringWithFormat:@"(%@)", self.portReview.author];
    }
    self.dateLabel.text = [NSString stringWithFormat:@"%@ %@", [dateFormatter stringFromDate:self.portReview.createdAt], authorString];

    // Rating can never exceed 5 bubbles. In case the rating provided is greater than 5, round down to 5.
    CGFloat roundedRating = MIN(round([self.portReview.rating floatValue] * 2) / 2, 5.0f);
    roundedRating = MAX(0, roundedRating);

    self.rating = roundedRating;

    if (self.rating > 0)
    {
        [self.contentView addSubview:self.ratingView];
        [self.ratingView setImage:[UIImage imageNamed:[NSString stringWithFormat:@"cc_bubbles_%.1f.png", roundedRating]]];
        if ([self.ratingLabel isDescendantOfView:self.contentView])
        {
            [self.ratingLabel removeFromSuperview];
        }
        if (self.ratingLabel.constraints)
        {
            [self.ratingLabel removeConstraints:self.ratingLabel.constraints];
        }
    }
    else
    {
        [self.contentView addSubview:self.ratingLabel];
        [self.ratingLabel setText:@"Not Rated"];
        if ([self.ratingView isDescendantOfView:self.contentView])
        {
            [self.ratingView removeFromSuperview];
        }
        if (self.ratingView.constraints)
        {
            [self.ratingView removeConstraints:self.ratingView.constraints];
        }
    }

    [self setLayout];
}

-(void)setLayout
{
    typeof (self) __weak weakSelf = self;

    // rating
    if (self.rating > 0)
    {
        [self.ratingView mas_makeConstraints:^(MASConstraintMaker *make) {
            make.top.equalTo(weakSelf.contentView.mas_top).with.offset(kPadding);
            make.left.equalTo(weakSelf.contentView.mas_left).with.offset(kPadding);
            make.height.equalTo(@20);
            make.width.equalTo(@100);
        }];
    }
    else
    {
        [self.ratingLabel mas_makeConstraints:^(MASConstraintMaker *make) {
            make.top.equalTo(weakSelf.contentView.mas_top).with.offset(kPadding);
            make.left.equalTo(weakSelf.contentView.mas_left).with.offset(kPadding);
            make.height.equalTo(@20);
            make.width.equalTo(@100);
        }];
    }

    // date label
    [self.dateLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        if (weakSelf.rating > 0)
        {
            make.top.equalTo(weakSelf.ratingView.mas_bottom).with.offset(kPadding);
        }
        else
        {
            make.top.equalTo(weakSelf.ratingLabel.mas_bottom).with.offset(kPadding);
        }
        make.left.equalTo(weakSelf.contentView.mas_left).with.offset(kPadding);
        make.right.equalTo(weakSelf.contentView.mas_right).with.offset(-kPadding);
    }];

    // description
    [self.descriptionLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(weakSelf.dateLabel.mas_bottom).with.offset(kPadding);
        make.left.equalTo(weakSelf.contentView.mas_left).with.offset(kPadding);
        make.right.equalTo(weakSelf.contentView.mas_right).with.offset(-kPadding);
        make.bottom.equalTo(weakSelf.contentView.mas_bottom).with.offset(-kPadding);
    }];
}

输出（背景为橙色以突出显示填充）：

Screen cap

为什么自动布局会添加此填充，我该如何摆脱它？它也会在应用程序的其他区域出现，所以我想了解它为什么会这样，所以我可以修复不需要的布局。

修改

为tableView:heightForRowAtIndexPath中的每一行计算高度，如下所示：

PortReviewTableViewCell* cell = self.autoLayoutCell;
cell.portReview = self.portReviews[indexPath.row];

// Since we have multi-line labels, do an initial layout pass and then set the preferredMaxLayoutWidth
// based on their width so they will wrap text and take on the correct height
[cell.contentView setNeedsLayout];
[cell.contentView layoutIfNeeded];
cell.descriptionLabel.preferredMaxLayoutWidth = CGRectGetWidth(cell.descriptionLabel.frame);

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

return height;

iOS 8.1.3在UILabel的顶部和底部添加了填充

0 个答案: