ios - 如何在自定义 UITableViewCell 中使用 PureLayout 显示图像？

Question

我正在 iOS 上创建一个图像投票应用程序。提要将是条目的实例，类似于发布的图像（无边框）。我UITableViewCell使用 PureLayout 创建了一个自定义。但是，图像（异步加载）不显示。

我invalidateIntrinsicContentSize在图像完成处理程序中尝试过类似的东西，但没有奏效。我是 AutoLayout 的新手，我正在关注这个示例代码

这是我对图像和 2 个顶部标签的约束设置

- (void) updateConstraints {
    if (!self.didSetupConstraints) {

        self.contentView.bounds = CGRectMake(0.0f, 0.0f, 99999.0f, 99999.0f);

        [NSLayoutConstraint autoSetPriority:UILayoutPriorityRequired forConstraints:^{
            [self.questionLabel autoSetContentCompressionResistancePriorityForAxis:ALAxisVertical];
        }];
        [self.questionLabel autoPinEdgeToSuperviewEdge:ALEdgeTop withInset:kLabelVerticalInsets];
        [self.questionLabel autoPinEdgeToSuperviewEdge:ALEdgeLeading withInset:kLabelHorizontalInsets];
        [self.questionLabel autoPinEdgeToSuperviewEdge:ALEdgeTrailing withInset:kLabelHorizontalInsets];


        [self.nameLabel autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.questionLabel withOffset:kLabelVerticalInsets];

        [NSLayoutConstraint autoSetPriority:UILayoutPriorityRequired forConstraints:^{
            [self.nameLabel autoSetContentCompressionResistancePriorityForAxis:ALAxisVertical];
        }];
        [self.nameLabel autoPinEdgeToSuperviewEdge:ALEdgeLeading withInset:kLabelHorizontalInsets];
        [self.nameLabel autoPinEdgeToSuperviewEdge:ALEdgeTrailing withInset:kLabelHorizontalInsets];
        [self.nameLabel autoPinEdgeToSuperviewEdge:ALEdgeBottom withInset:kLabelVerticalInsets];



        [NSLayoutConstraint autoSetPriority:UILayoutPriorityRequired forConstraints:^{
            [self.mainImageView autoSetContentCompressionResistancePriorityForAxis:ALAxisVertical];
        }];

        [self.mainImageView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.nameLabel withOffset:kLabelVerticalInsets];

        [self.mainImageView autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:0];
        [self.mainImageView autoPinEdgeToSuperviewEdge:ALEdgeRight withInset:0];
        [self.mainImageView autoPinEdgeToSuperviewEdge:ALEdgeBottom withInset:0];


        self.didSetupConstraints = YES;
    }

    [super updateConstraints];
}