使用 30MB 随机数据文件提取数据真的很慢 [英] Extract data really slow with a 30MB random data file

问题描述

我有一个大约 215,000 行的文本文件.逐行及其随机数据，最后一行我有这个strA123456strB"

I have a text file with about 215,000 lines. line by line and its random data and on the last line I have this "strA123456strB"

在我的电脑上处理这个大约需要 2 秒，但我试图将处理时间减少到几毫秒..有什么建议吗?

to process this its taking about 2 seconds on my computer but I am trying to reduce the processing time to just milliseconds.. any suggestions ?

我这样称呼它

GetStringBetween(RichTextBox.Text, "strA", "strB")

这是vb.net源

Function GetStringBetween(ByVal allData As String, ByVal str1 As String, ByVal str2 As String) As String
    Dim foundstr As String = Nothing
    Dim i As Integer = allData.ToUpper().IndexOf(str1.ToUpper())
    Dim j As Integer
    If i > -1 Then
        allData = allData.Substring(i + str1.Length)
        j = allData.ToUpper().IndexOf(str2.ToUpper())
        If j > -1 Then
            foundstr = allData.Substring(0, j)
        End If
    End If
    Return foundstr
End Function

推荐答案

以下是使用 Regex 进行搜索的简单示例:

Here is an simple example for between search using Regex:

Dim allData = "nonmatch2_strA_match_strB_nonmatch2"
Dim r = Regex.Match(allData, "strA(.*)strB")

要忽略大小写，请使用 RegexOptions:

To ignore case, use RegexOptions:

Dim r = Regex.Match(allData, "strA(.*)strB", RegexOptions.IgnoreCase)

r = 行执行完毕后，你可以得到它找到的值，如下所示:

After the r = line finished execution, you can get the value it found like this:

r.Groups(1).Value 

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