Question

如何在另一个字符串中搜索字符串，然后选择所有字符直到行尾？例如，给定此字符串：

PrinterName：PDFCreator

PortName：PDFCreator：

状态：未知

DriverName：PDFCreator

PrinterName：Lexmark E360dn XL

PortName：someport

状态：未知

DriverName：Lexmark E360dn XL

HostAddress：somehostaddress

我想搜索字符串：“PrinterName”一旦找到它，将其添加到组合框中，以便只获取PrinterName。到目前为止我写了这个：

Dim TextSearched As String = tmp.Text
    Dim Paragraph As String = "PrinterName:"
    Dim location As Integer = 0
    Dim occurances As Integer = 0

    Do

        location = TextSearched.IndexOf(Paragraph, location)

        If location <> -1 Then

            occurances += 1
            If TextSearched.EndsWith(vbCrLf) Then

                Debug.Print(TextSearched.Substring(location, TextSearched.IndexOf(vbCrLf)))

            End If
            location += Paragraph.Length

        End If



    Loop Until location = -1

其中tmp.Text是一个长字符串，如上例所示。

当我运行它时，我得到这样的东西：

PrinterName：PDFCreator

PrinterName：Lexmark E3

我没有得到“360dn XL”

Answer 1

这涉及使用IndexOf和SubString Extension Methods进行一些简单的解析。下面是一个将所有PrinterName值放入List（String）的示例。：

    Dim lstLines As List(Of String) = IO.File.ReadAllLines("C:\Your\Location\tmp.txt").ToList()

    Dim lstPrinters As New List(Of String)

    lstLines.ForEach(Sub(strLine As String)
                         If strLine.IndexOf("PrinterName:") > -1 Then
                             lstPrinters.Add(strLine.Substring(strLine.IndexOf("PrinterName:") + 13))
                         End If
                     End Sub)

Answer 2

您是否考虑过使用Regex？您可以使用如下模式：

"PrinterName: (.*?)\r\n"

哪个应该在长字符串中找到该行并将数据捕获到组1中。您可以像这样访问结果：

Imports System.Text.RegularExpressions

Module Module1
    Sub Main()
        Dim TextSearch As String = _
            "PrinterName : PDFCreator()" + vbCrLf + _
            "PortName: PDFCreator()" + vbCrLf + _
            "Status: Unknown()" + vbCrLf + _
            "DriverName: PDFCreator()" + vbCrLf + _
            "PrinterName: Lexmark E360dn XL" + vbCrLf + _
            "PortName: someport()" + vbCrLf + _
            "Status: Unknown()" + vbCrLf + _
            "DriverName: Lexmark E360dn XL" + vbCrLf + _
            "HostAddress: somehostaddress()"

        Dim Matcher = Regex.Match(TextSearch, "PrinterName: (.*?)\r\n")
        If Matcher.Success Then
            Console.WriteLine(Matcher.Groups(1))
        End If
    End Sub
End Module

结果：

Lexmark E360dn XL

您可以将Matcher.Groups(1)添加到组合框中。

Answer 3

另一个......

FormsAuthentication.SetAuthCookie(username, "false");

这也可以写成：

    Dim TextSearch As String =
        "PrinterName : PDFCreator()" + vbCrLf +
        "PortName: PDFCreator()" + vbCrLf +
        "Status: Unknown()" + vbCrLf +
        "DriverName: PDFCreator()" + vbCrLf +
        "PrinterName: Lexmark E360dn XL" + vbCrLf +
        "PortName: someport()" + vbCrLf +
        "Status: Unknown()" + vbCrLf +
        "DriverName: Lexmark E360dn XL" + vbCrLf +
        "HostAddress: somehostaddress()"

    Dim printers As List(Of String) = TextSearch.Split(vbCrLf.ToCharArray, StringSplitOptions.RemoveEmptyEntries).Where(Function(x) x.ToLower.StartsWith("printername")).Select(Function(x) x.Split(":").Last).ToList
    For Each printer As String In printers
        Debug.Print(printer)
    Next

VB NET字符串搜索

3 个答案: