两个文本垂直中心点固定不变

问题描述

如图所示，页面上下并排显示两条文本，文本动态变化，要求两条文本上下边之间的中心点（即图中蓝色箭头所指的位置）始终位于页面的 centerY 的位置。

解决方案

根据要显示的文本，生成富文本，两条文本的间距映射为富文本的段间距。然后设置 label.centerY.equalToSuperview()

        let str1 = "fakdjkaljfkldajfkdalkfda111\n"
        let str2 = "abcdfefkddakghdalkgj"
        let muAttStr1: NSMutableAttributedString = NSMutableAttributedString.init(string: str1)
        let paragraph1 = NSMutableParagraphStyle()
        paragraph1.paragraphSpacing = 10
        let dic = [NSAttributedString.Key.font:UIFont.systemFont(ofSize: 20),
                   NSAttributedString.Key.paragraphStyle:paragraph1,
                   NSAttributedString.Key.backgroundColor:UIColor.red]
        muAttStr1.addAttributes(dic, range: NSMakeRange(0, str1.count))
        
        let dic2 = [NSAttributedString.Key.font:UIFont.systemFont(ofSize: 10)]
        let muAttStr2: NSAttributedString = NSAttributedString.init(string: str2, attributes: dic2)
        
        muAttStr1.append(muAttStr2)
        desLabel.attributedText = muAttStr1.copy() as? NSAttributedString
        view.addSubview(desLabel)
        desLabel.snp.makeConstraints() { (make) in
            make.leading.equalToSuperview().offset(10)
            make.trailing.equalToSuperview().offset(-200)
            make.centerY.equalToSuperview()
        }