试图搜索具有起始点和结束点的字符串

Question

我需要搜索一些字符串，并寻找一个特定的区域开始和走，直到它找到终点，两个点之间的距离将在整个字符串中变化，所以我不能使用基于长度的东西。

下面是我要寻找的一个字符串的示例

IF (SUBSTRING(A.DATE_QUOTE_CNV,1,4) >= '1900' AND SUBSTRING(A.DATE_QUOTE_CNV,1,4) <= '2999' AND SUBSTRING(A.DATE_QUOTE_CNV,5,2) <= '12' AND SUBSTRING(A.DATE_QUOTE_CNV,5,2) >= '01' AND SUBSTRING(A.DATE_QUOTE_CNV,7,2) <= '31' AND SUBSTRING(A.DATE_QUOTE_CNV,7,2) >= '01',CONCAT(SUBSTRING(A.DATE_QUOTE_CNV,1,4),'-',SUBSTRING(A.DATE_QUOTE_CNV,5,2),'-',SUBSTRING(A.DATE_QUOTE_CNV,7,2)))"

我想使用的起点是"IF (SUBSTRING(“和我希望结束点为”7，2)“，因为这两个点始终保持一致。我该怎么做？

Answer 1

获取起始点和结束点的索引，并使用它们从搜索查询中获取子字符串。

你可以用这样的东西。

' stringToSearch is the value you want to search
    ' 
    Dim stringToSearch As String = "<SomeText>IF (SUBSTRING(A.DATE_QUOTE_CNV,1,4) >= '1900' AND SUBSTRING(A.DATE_QUOTE_CNV,1,4) <= '2999' AND SUBSTRING(A.DATE_QUOTE_CNV,5,2) <= '12' AND SUBSTRING(A.DATE_QUOTE_CNV,5,2) >= '01' AND SUBSTRING(A.DATE_QUOTE_CNV,7,2) <= '31' AND SUBSTRING(A.DATE_QUOTE_CNV,7,2) >= '01',CONCAT(SUBSTRING(A.DATE_QUOTE_CNV,1,4),'-',SUBSTRING(A.DATE_QUOTE_CNV,5,2),'-',SUBSTRING(A.DATE_QUOTE_CNV,7,2)))<SomeText>"

    Dim startPoint As String = "IF (SUBSTRING("
    Dim endPoint As String = "7,2)))"
    Dim result As String = String.Empty

    If stringToSearch.Contains(startPoint) And stringToSearch.Contains(endPoint) Then

        Dim startIndex = stringToSearch.IndexOf(startPoint)
        Dim endIndex = stringToSearch.IndexOf(endPoint)

        ' search result
        result = stringToSearch.Substring(startIndex, endIndex - startIndex + endPoint.Length)

    End If