像WhatsApp

Question

private func setTitle(title:String, subtitle:String, animate: Bool) -> UIView {
    let titleLabel = UILabel(frame: CGRect(x:0, y:-5, width:0, height:0))

    titleLabel.backgroundColor = UIColor.clear
    titleLabel.textColor = UIColor.gray
    titleLabel.font = UIFont.boldSystemFont(ofSize: 15)
    titleLabel.text = title
    titleLabel.adjustsFontSizeToFitWidth = true

    let subtitleLabel = UILabel(frame: CGRect(x:0, y:18, width:0, height:0))
    subtitleLabel.backgroundColor = UIColor.clear
    subtitleLabel.textColor = UIColor.black
    subtitleLabel.font = UIFont.systemFont(ofSize: 12)
    subtitleLabel.text = subtitle
    subtitleLabel.adjustsFontSizeToFitWidth = true


    let titleView = UIView(frame: CGRect(x:0, y:0, width:max(titleLabel.frame.size.width, subtitleLabel.frame.size.width), height:30))
    let titleViewTapGesture = UITapGestureRecognizer(target: self, action: #selector(titleViewTapped(sender:)))
    titleView.addGestureRecognizer(titleViewTapGesture)
    titleView.addSubview(titleLabel)

    if animate{
        subtitleLabel.alpha = 0.0
        titleView.addSubview(subtitleLabel)

        UIView.animate(withDuration: 1) { () -> Void in
            subtitleLabel.alpha = 1.0
        }

    }else{
        titleView.addSubview(subtitleLabel)
    }

    let widthDiff = subtitleLabel.frame.size.width - titleLabel.frame.size.width

    if widthDiff > 0 {
        var frame = titleLabel.frame
        frame.origin.x = widthDiff / 2
        titleLabel.frame = frame.integral
    } else {
        var frame = subtitleLabel.frame
        frame.origin.x = abs(widthDiff) / 2
        titleLabel.frame = frame.integral
    }

    return titleView
}

这就是我在navigationItem

上设置标题的方式

        self.navigationItem.titleView = setTitle(title: "DEMO NAME TO TEST TITLE", subtitle: "tap here to get info", animate: false)

但看起来像

如何通过subTitle折叠修复该标题？我不介意在标题上显示“......”（没有多行）。

Answer 1

您可以使用以下功能实现此功能：

func setTitle(title:String, subtitle:String) -> UIView {

        let titleLabel = UILabel(frame: CGRect(x: 0, y: -2, width: 0, height: 0))

        titleLabel.backgroundColor = UIColor.clear
        titleLabel.textColor = UIColor.gray
        titleLabel.font = UIFont.boldSystemFont(ofSize: 17)
        titleLabel.text = title
        titleLabel.sizeToFit()

        let subtitleLabel = UILabel(frame: CGRect(x:0, y:18, width:0, height:0))
        subtitleLabel.backgroundColor = .clear
        subtitleLabel.textColor = .black
        subtitleLabel.font = UIFont.systemFont(ofSize: 12)
        subtitleLabel.text = subtitle
        subtitleLabel.sizeToFit()


        let titleView = UIView(frame: CGRect(x: 0, y: 0, width: max(titleLabel.frame.size.width, subtitleLabel.frame.size.width), height: 30))
        titleView.addSubview(titleLabel)
        titleView.addSubview(subtitleLabel)

        let widthDiff = subtitleLabel.frame.size.width - titleLabel.frame.size.width

        if widthDiff < 0 {
            let newX = widthDiff / 2
            subtitleLabel.frame.origin.x = abs(newX)
        } else {
            let newX = widthDiff / 2
            titleLabel.frame.origin.x = newX
        }

        return titleView
    }

并且这样打电话：

self.navigationItem.titleView = setTitle(title: "Title Title Title", subtitle: "ello Shabir how are you")

结果是这样的：