用两条线截断UILabel的头部

Question

我有一个UIlabel，其numberOfLines为2 和lineBreakMode = Truncate Head

但是当我跑的时候 而不是像第一行那样在第一行截断头部

    ...1st Line Content
    2nd Line Content

它像

一样截断

    1st Line Content 
    ...2nd Line Content

如何在第一行中截断标签的头部？

Answer 1

尝试在Swift 3

中测试此代码

   let text = "Hello World! Hello World! Hello World! Hello World! "
    let attString = NSMutableAttributedString(string: text)
    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = .left 
    paragraphStyle.firstLineHeadIndent = 0
    paragraphStyle.headIndent = 40 // set any vallue
    paragraphStyle.lineBreakMode = .byTruncatingHead
    attString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attString.length))
    attString.addAttribute(NSFontAttributeName, value: UIFont(name: "Arial", size: 25)!, range: NSMakeRange(0, attString.length))
    label.attributedText = attString // label is your UILabel
    label.numberOfLines = 2

输出1：

    paragraphStyle.firstLineHeadIndent = 40 // set any vallue
    paragraphStyle.headIndent = 0 

输出2：

更新：您可以通过合并两个属性字符串

来实现

    let dotAttributes = [NSForegroundColorAttributeName: UIColor.red, NSFontAttributeName: UIFont(name: "Arial", size: 25)]
    let textAttributes = [NSForegroundColorAttributeName: UIColor.red, NSFontAttributeName: UIFont(name: "Arial", size: 25)]

    let dotString = NSMutableAttributedString(string: ". . . ", attributes: dotAttributes)
    let textString = NSMutableAttributedString(string: "Hello World! Hello World! Hello World! Hello World!", attributes: textAttributes)

    let totalString = NSMutableAttributedString()
    totalString.append(dotString)
    totalString.append(textString) 

    label.numberOfLines = 2
    label.attributedText = totalString

注意：您可以使用paragraphStyle（headIndent）创建左边距。

    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = .left 
    paragraphStyle.firstLineHeadIndent = 5
    paragraphStyle.headIndent = 5 // set any vallue
    paragraphStyle.lineBreakMode = .byTruncatingHead
    totalString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, totalString.length))

输出：