如何用 vb.net 替换此字符串的某些部分？

Question

我正在寻求创建正则表达式的帮助，以便我可以用锚标记替换文本。文本来自 SQL 字段 (VarChar(max))，格式如下：

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (1954, c. 12; 1968, c. 300; 1994, c. 98)

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (1998, cc. 553, 568; 2001, c. 300)

在上面的文字中，我需要将 1994 年之后的所有章节替换为锚标签。因此，例如，98、553、568 和 300 都将被替换。以下代码查找 1994 年的整个文本，例如 c.98，但我不确定如何仅替换该文本中的“98”。

Public Shared Function ReplaceChapterTag1(lang As String) As String
    Dim l As String = lang
    Dim r As Regex = New Regex("199[4-9][/,][/ ][/c]*[/.][/ ][0-9]+(?:\.[0-9]*)?")

    Dim applyEvaluator As MatchEvaluator = New MatchEvaluator(AddressOf applyCodeLink)
    l = r.Replace(l, applyEvaluator)

    Return l

End Function

Private Shared Function applyCodeLink(ByVal m As Match) As String
    Dim r As Regex = New Regex("^[0-9]*[\-][0-9]*")
    Dim str As String = m.ToString
    Dim strReturn As String = ""

    Dim match As Match = r.Match(str)
    If match.Success Then
        strReturn = str
    Else
        strReturn = "<a href='link?id=" & m.Value & "'>" & m.Value & "</a>"
    End If

    Return strReturn
End Function

Answer 1

解决方案

我不确定如何仅替换该文本中的“98”。

您可以使用Regex.Replace。但是，您构建的正则表达式需要像这样调整：

(?<=199[4-9][^;]+)(?<=[/c]*[/.][/\x20]|,\x20)(\d+(?:\.\d*)?)(?=[,;)])

说明

示例代码

' Input
Dim InputText As String = "..." ' Lorem ipsum...

' Regex
Dim r As Regex = New Regex( _
      "(?<=199[4-9][^;]+)" + _
      "(?<=[/c]*[/.][/\x20]|,\x20)" + _
      "(\d+(?:\.\d*)?)" + _
      "(?=[,;)])", _
    RegexOptions.IgnoreCase _
    Or RegexOptions.CultureInvariant _
    Or RegexOptions.Compiled _
    )

' This is the replacement string
Dim Replacement As String = "<a href='link?id=$1'>$1</a>"

'' Replace the matched text in the InputText using the replacement pattern
Dim Result As String = r.Replace(InputText,Replacement)

输入

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (1954, c. 12; 1968, c. 300; 1994, c. 98)

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (1998, cc. 553, 568; 2001, cc. 17, 300)

输出

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (1954, c. 12; 1968, c. 300; 1994, c. <a href='link?id=98'>98</a>)

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (1998, cc. <a href='link?id=553'>553</a>, <a href='link?id=568'>568</a>; 2001, cc. 17, 300)

讨论

基本上，在我的回答中调整正则表达式背后的想法是寻找一个或多个数字（\d+），它们前面和后面跟着一些字符。

我冒昧地简化并明确了初始正则表达式。主要是我换了：

• [0-9] 与 \d
• (space char) 与 \x20