导航栏标题视图上的多行UILabel

Question

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我有一个自定义UIView，它具有2个UILabel（相同的宽度）和一个UIImageView（已知的44pt宽度）。宽度大小仅作为示例提供，可以更改，但是UILabels的宽度应相同，UIImage的宽度为44点。我想将此视图添加到UINavigationBar'titleView，但ImageView应该在导航栏的center中。

(60 width) UILabel---UIImageView (44 width) ---UILabel (60 width)

我想要是UILabel最多具有两行且adJustFontSizeToFitWidth为true。我给标题视图指定了特定的宽度和高度，但是标签只有两行，但是即使它们不适合视图，它们的字体大小也不会改变。

我如何添加titleView：

 navigationItem.titleView = myTitleView
    let widthOfItem: CGFloat = 30.0
    let pading: CGFloat = 40
    let aWidth: CGFloat = (self.navigationController?.navigationBar.frame.width)! - CGFloat(1) * widthOfItem * 2.0 - pading

    myTitleView { (make) in
        make.width.equalTo(aWidth)
        make.height.equalTo(44)
    }

MyCustomView：

override func layoutSubviews() {
    super.layoutSubviews()
    let preferredWidth = (bounds.width / 2) - 56
    firstLabel.preferredMaxLayoutWidth = preferredWidth
    secondLabel.preferredMaxLayoutWidth = preferredWidth
}

private func setupViews() {

    addSubview(firstLabel)
    addSubview(myImageView)
    addSubview(secondLabel)

    firstLabel.font = .myFont(.bold, size: 36)
    firstLabel.adjustsFontSizeToFitWidth = true
    firstLabel.minimumScaleFactor = 0.5
    firstLabel.textColor = .textPrimary
    firstLabel.numberOfLines = 2
    firstLabel.lineBreakMode = .byWordWrapping
    firstLabel.textAlignment = .right

    myImageView.contentMode = .scaleAspectFit
    myImageView.clipsToBounds = true
    myImageView.layer.minificationFilter = .trilinear
    myImageView.layer.cornerRadius = currencyImageSize.height / 2

    secondLabel.font = . myFont(.bold, size: 36)
    secondLabel.translatesAutoresizingMaskIntoConstraints = false
    secondLabel.textColor = .textPrimary
    secondLabel.numberOfLines = 2
    secondLabel.adjustsFontSizeToFitWidth = true
    secondLabel.baselineAdjustment = .none
    secondLabel.minimumScaleFactor = 0.5
    secondLabel.lineBreakMode = .byWordWrapping
    secondLabel.textAlignment = .left

    firstLabel.snp.makeConstraints { (make) in
        make.leading.equalToSuperview()
        make.top.bottom.equalToSuperview()
        make.trailing.equalTo(myImageView.snp.leading).offset(-12)
    }

    myImageView.snp.makeConstraints { (make) in
        make.height.equalToSuperview()
        make.width.equalTo(myImageView.snp.height)
        make.centerX.equalToSuperview()
    }
   secondLabel.snp.makeConstraints { (make) in
        make.top.bottom.equalToSuperview()
        make.leading.equalTo(myImageView.snp.trailing).offset(12)
        make.trailing.equalToSuperview()
    }
}

Answer 1

也许此代码会起作用？

class CustomNavClass: UIView {

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup_view()
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup_view()
    }

    private func setup_view() {
        backgroundColor = .lightGray

        let image = UIImageView(image: .init())
        addSubview(image)

        image.translatesAutoresizingMaskIntoConstraints = false
        image.backgroundColor = .green

        NSLayoutConstraint.activate([
            image.centerXAnchor.constraint(equalTo: centerXAnchor),
            image.widthAnchor.constraint(equalToConstant: 44),
            image.heightAnchor.constraint(equalToConstant: 44),

            image.topAnchor.constraint(equalTo: topAnchor, constant: 3),
            image.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -3)
        ])

        let leftLabel = UILabel()
        leftLabel.text = "Label label left long label will go here, naturally"
        leftLabel.numberOfLines = 2
        leftLabel.adjustsFontSizeToFitWidth = true
        leftLabel.backgroundColor = .red

        addSubview(leftLabel)

        leftLabel.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            leftLabel.leadingAnchor.constraint(equalTo: leadingAnchor),
            leftLabel.centerYAnchor.constraint(equalTo: centerYAnchor),
            leftLabel.trailingAnchor.constraint(equalTo: image.leadingAnchor, constant: -10)
        ])

        let rightLabel = UILabel()
        rightLabel.text = "Label label right long label will go here, naturally"
        rightLabel.numberOfLines = 2
        rightLabel.adjustsFontSizeToFitWidth = true
        rightLabel.backgroundColor = .blue

        addSubview(rightLabel)

        rightLabel.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            rightLabel.trailingAnchor.constraint(equalTo: trailingAnchor),
            rightLabel.centerYAnchor.constraint(equalTo: centerYAnchor),
            rightLabel.leadingAnchor.constraint(equalTo: image.trailingAnchor, constant: 10)
        ])
    }
}

代码不使用UIStackView作为其功能的限制（具体地说，在UIView .fill属性上只能扩展一个distribution。

这将创建布局约束：

UIImageView固定的[center（顶部和底部约束为3，可选，您可以使用centerY约束等）。
1. UILabel的前缘与UIImageView的前缘与后缘挂钩。
2. 尾随UILabel与尾沿和前沿与UIImageView的尾沿挂钩。