VB.Net 从某些单词之后获取字符

Question

我试图从字符串中“提取”一个数字，方法是使用以下简单代码在: 处拆分字符串，然后只使用结果的前几个字符。然而，实际的现实世界字符串包含两个数字，前面有一个 :，我只想从字符串中拉出其中一个，但这给我带来了一些问题。我正在尝试从字符串的以下部分中提取数字：Our Ref: 200018 但拆分功能似乎只支持一个字符进行拆分。在现实世界中，这个数字变化很大，但长度保持不变 8 个字符。

我怎样才能只从Our Ref: 200018 中提取数字而不 Your Ref: 265845 在代码中与它混淆？

Dim sOutput As String = "This is an example string Our Ref: 200018 Your Ref: 265845 did this work?"
Dim word As String = sOutput
Dim wordArr As String() = word.Split(":")
MsgBox("Result: " & wordArr(1).ToString)

Answer 1

你可以使用Regex:

Dim sOutput As String = "This is an example string Our Ref: 200018 Your Ref: 265845 did this work?"
Dim m As Match = Regex.Match(sOutput, "\bOur Ref\b\:\s*(\d+)", RegexOptions.IgnoreCase)

If m.Success = True Then 'Match found.
    Dim Ref As Integer = Integer.Parse(m.Groups(1).Value)
    MessageBox.Show(Ref)
End If

需要进口：

Imports System.Text.RegularExpressions

此代码不区分大小写，因此它也会匹配 oUr rEF 或 OUR REF（等）。

在线测试：http://ideone.com/DetTxq

模式解释：

\bOur Ref\b\:\s*(\d+)

\b         =>  Word boundary, means that it should match whole words (i.e. only "Our Ref" and not "Your Ref", etc.).
Our Ref    =>  Match the words "Our Ref".
\:         =>  Match a colon.
\s*        =>  Match zero or more spaces.
(          =>  Start of match group.
    \d+    =>  Match one or more numerical characters.
)          =>  End of match group.

匹配组是“子匹配”，其值可以通过Match.Groups(<group index>).Value 访问。组索引 0 是整个匹配项。

阅读更多：

• Regex class - MSDN

• Match.Groups property - MSDN

• Regular Expressions Language - Quick Reference - MSDN

Answer 2

Dim sOutput As String = "This is an example string Our Ref: 200018 Your Ref: 265845 did this work?"
Dim word As String() = New String() {"Our Ref: "} 
Dim wordArr As String() = sOutput.Split(word,StringSplitOptions.RemoveEmptyEntries)

然后从示例中的子字符串中取出前 8 个字符：

Dim str As String = wordArr(1).Substring(0,7)

更多信息：Here