Vb.net 使用Visual Basic查找和替换txt文档中的文本

您好，我使用的是Visual Basic 2008 Express Edition，我的目标是读取作为模板的整个.txt文件，并在您按下命令按钮时将单词的所有文档替换为新文档，并将新修改的文本保存为新的.txt。有人能给我一些建议吗？

试试下面的例子，希望能有所帮助

 Dim lOpenFile As Long
 Dim sFileText As String
 Dim sFileName As String

sFileName = "C:\test.txt"

 'open the file and read it into a variable
 lOpenFile = FreeFile
 Open sFileName For Input As lOpenFile
 sFileText = Input(LOF(lOpenFile), lOpenFile)
 Close lOpenFile

'change 'John Doe' to 'Mary Brown'
 sFileText = Replace(sFileText, " John Doe ", " Mary Brown ")

 'write it back to the file
 lOpenFile = FreeFile
 Open sFileName For Output As lOpenFile
 Print #lOpenFile, sFileText
 Close lOpenFile

因此，您应该使用文件系统的ReadAllText方法，将路径作为参数传递，并使用Replace方法替换要替换的内容。有关replace的更高级用法，可以使用正则表达式。你可以读一下

较短版本：

My.Computer.FileSystem.WriteAllText("C:\test2.txt", My.Computer.FileSystem.ReadAllText("C:\test.txt").Replace("foo", "bar"), False)

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我是从我正在制作的一个程序中提取出来的，只是去掉你不需要的废话

Private Sub UPDATECODES_Click(sender As Object, e As EventArgs) Handles UPDATECODES.Click
    Dim NEWCODE As String = NEWCODEBOX.Text
    Dim CC As String = CURRENTCODE.Text
    Dim oldcode As String
    Dim codelines(0 To 1) As String
    Dim olddate As String

    Using r1 As New System.IO.StreamReader(CODEDIR & "d.dat")
        olddate = r1.ReadToEnd
    End Using

    Using r2 As New System.IO.StreamReader(CODEDIR & "oc.dat")
        oldcode = r2.ReadToEnd
    End Using

    If System.IO.File.Exists(CODEDIR & "new code.txt") Then
        System.IO.File.Delete(CODEDIR & "new code.txt")
    End If

    If System.IO.File.Exists(CODEDIR & "CC.DAT") Then
        If IO.File.Exists(CODEDIR & "oc.dat") Then
            IO.File.Delete(CODEDIR & "OC.DAT")
        End If

        My.Computer.FileSystem.RenameFile(CODEDIR & "CC.DAT", "OC.DAT")
        Dim FILESTREAM As System.IO.FileStream
        FILESTREAM = New System.IO.FileStream(CODEDIR & "CC.DAT", System.IO.FileMode.Create)
        FILESTREAM.Close()
    End If

    Using WRITER As New System.IO.StreamWriter(CODEDIR & "CC.DAT")
        WRITER.WriteLine(NEWCODE)
    End Using

    Dim currentlines(0 To 1) As String
    Dim a As Integer
    Dim TextLine(0 To 1) As String
    a = 0

    Using sr As New System.IO.StreamReader(CODEDIR & "internet code.txt")
        While Not sr.EndOfStream
            ReDim codelines(0 To a)
            codelines(a) = sr.ReadLine()
            codelines(a) = codelines(a).Replace(CURRENTCODE.Text, NEWCODE)
            codelines(a) = codelines(a).Replace(olddate, DATEBOX1.Text & " - " & DATEBOX2.Text)
            Dim newfile As String = (CODEDIR & "new code.txt")
            Using sw As New System.IO.StreamWriter(newfile, True)
                sw.WriteLine(codelines(a))
            End Using
            a = a + 1
        End While
    End Using

    Using sw2 As New System.IO.StreamWriter(CODEDIR & "d.dat")
        sw2.WriteLine(date1 & " - " & date2)
    End Using

    System.IO.File.Delete(CODEDIR & "internet code.txt")
    My.Computer.FileSystem.RenameFile(CODEDIR & "new code.txt", "internet code.txt")
    CURRENTCODE.Text = NEWCODE
End Sub

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我有一个我写的小程序，我用它来重用代码。当我需要创建一个与现有类或代码文件几乎相同的类或代码文件时，我会使用它。它是一个基本表单程序，有四个文本框和一个按钮，除了字符串没有硬编码外，它使用与接受答案相同的命令

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

  Dim source As String = txtSource.Text
  Dim destination As String = txtDestination.Text
  Dim oldText As String = txtOldText.Text
  Dim newText As String = txtNewText.Text

  My.Computer.FileSystem.WriteAllText(destination, My.Computer.FileSystem.ReadAllText(source).Replace(oldText, newText), False)

End Sub

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未声明错误1“打开”。文件I/O功能在“Microsoft.VisualBasic”命名空间中可用。C:\Users\EMACFEL\AppData\Local\Temporary Projects\WindowsApplication1\Form1.vb 32 9 WindowsApplication1使用System.IoTS添加系统IO我复制粘贴了您的代码在命令按钮单击事件中，当我构建程序时，当我点击按钮时，文本文件中仍然充满了foo，但没有替换完成。我明白了。字符串文件读取器包含正确的文本，对吗？您的问题是文件没有刷新。我的代码只用于阅读文本，尚未完成编写，但我很快会更新我的代码。好的，我添加了

My.Computer.FileSystem.writealText（“C:\Users\EMACFEL\Documents\test.txt”，fileReader，False）

，它成功了thanks@DNA180，这可能可以用正则表达式实现。没关系，我在这里找到了。这是做什么的？“只需删掉你不需要的废话”——你没有解释代码的作用，删掉代码不是更容易吗？

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

  Dim source As String = txtSource.Text
  Dim destination As String = txtDestination.Text
  Dim oldText As String = txtOldText.Text
  Dim newText As String = txtNewText.Text

  My.Computer.FileSystem.WriteAllText(destination, My.Computer.FileSystem.ReadAllText(source).Replace(oldText, newText), False)

End Sub