如何压缩UILabel顶部和底部的额外填充

Question

请参阅所附的屏幕截图，当文本内容较少时，我看到在UILabel的顶部和底部添加了额外的填充。

但是当dummyDescription Label文本更多时，效果很好。仅当dummyDescriptionLabel较小时才会发生问题。

下面是我的约束，这些约束是通过编程方式添加的

NSLayoutConstraint.activate([
            self.dummyImageView.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 24),
            self.dummyImageView.topAnchor.constraint(equalTo: self.topAnchor,constant:24),
            self.dummyImageView.widthAnchor.constraint(equalToConstant: 105),
            self.dummyImageView.heightAnchor.constraint(equalToConstant: 67),

            self.dummyNameLabel.topAnchor.constraint(equalTo: self.dummyImageView.topAnchor),
            self.dummyNameLabel.leadingAnchor.constraint(equalTo: self.dummyImageView.trailingAnchor, constant: 16),
            self.dummyNameLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -24),

            self.dummyDescriptionLabel.topAnchor.constraint(equalTo: self.dummyImageView.bottomAnchor, constant: 16),
            self.dummyDescriptionLabel.leadingAnchor.constraint(equalTo: self.dummyImageView.leadingAnchor),
            self.dummyDescriptionLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -24),


            self.dummyButton.topAnchor.constraint(equalTo: self.dummyDescriptionLabel.bottomAnchor, constant: 5),
            self.dummyButton.leadingAnchor.constraint(equalTo: self.dummyImageImageView.leadingAnchor),
            self.readMoreButton.heightAnchor.constraint(equalToConstant: 20)
        ])

我还在下面设置了仍然没有运气的

self.dummyNameLabel.setContentHuggingPriority(UILayoutPriority.defaultHigh, for: .horizontal)
self.dummyDescriptionLabel.setContentHuggingPriority(UILayoutPriority.defaultHigh, for: .horizontal)

任何帮助将不胜感激。

Answer 1

应该为垂直约束设置内容拥抱优先级。即

   self.dummyNameLabel.setContentHuggingPriority(UILayoutPriority.defaultHigh, for: .horizontal)
   self.dummyDescriptionLabel.setContentHuggingPriority(UILayoutPriority.defaultHigh, for: .horizontal)

应替换为：

    self.dummyNameLabel.setContentHuggingPriority(UILayoutPriority.defaultHigh, for: .vertical)
    self.dummyDescriptionLabel.setContentHuggingPriority(UILayoutPriority.defaultHigh, for: .vertical)

这样，标签的框架将始终与内部内容的高度相同。

类似地，为防止标签内容被其边界限制，您可以将垂直压缩优先级设置为默认值高。