VB.net如何提取system并修改文件安全属性？

将以下代码保存到模块中：

Declare Function GetPrivateProfileString Lib "kernel32" Alias _

"GetPrivateProfileStringA" (ByVal lpApplicationName As String, _

ByVal lpKeyName As Any, _

ByVal lpDefault As String, _

ByVal lpReturnedString As String, _

ByVal nSize As Long, _

ByVal lpFileName As String) As Long

Declare Function WritePrivateProfileStringByKeyName&Lib "kernel32" Alias _

"WritePrivateProfileStringA" (ByVal lpApplicationName As String, _

ByVal lpKeyName As String, _

ByVal lpString As String, _

Public Function GetIniParam(NomFichier As String, NomSection As String, NomVariable As String) As String

Dim ReadString As String * 255

Dim returnv As String

Dim mResultLen As Integer

mResultLen = GetPrivateProfileString(NomSection, NomVariable, "(Unassigned)", ReadString, Len(ReadString) - 1, NomFichier)

If IsNull(ReadString) Or Left$(ReadString, 12) = "(Unassigned)" Then

Dim Tempvalue As Variant

Dim Message As String

Message = "配置文件 " &NomFichier &" 不存在."

returnv = ""

Else

returnv = Left$(ReadString, InStr(ReadString, Chr$(0)) - 1)

End If

GetIniParam = returnv

End Function

Public Function WriteWinIniParam(NomDuIni As String, sLaSection As String, sNouvelleCle As String, sNouvelleValeur As String)

Dim iSucccess As Integer

iSucccess = WritePrivateProfileStringByKeyName(sLaSection, sNouvelleCle, sNouvelleValeur, NomDuIni)

If iSucccess = 0 Then

WriteWinIniParam = False

Else

WriteWinIniParam = True

End If

End Function

调用方法：

Call WriteWinIniParam(App.Path &"\LiveUpdate.ini", "LiveUpdate", "AppName", txtAppName.Text)

txtFile.Text = GetIniParam(App.Path &"\LiveUpdate.ini", "LiveUpdate", "FILES1")

.or Example:

1.txt文件内容如下:

The 1st line.

#The 2nd line.

The 3rd line.

The 4th line.

.

修改第二行内容,将#除去.修改后的文本如下:

The 1st line.

The 2nd line.

The 3rd line.

The 4th line.

1 输入方式打开原文件 1.txt；

2 输出方式打开新文件 2.txt；

3 逐行 Line Input 从 1.txt 中读数据，Print 写入 2.txt，直至要修改的行；

4 丢弃从 1.txt中读出的要修改的行，将新内容行写入 2.txt；

5 仿照第 3 步，将其余的行从 1.txt 复制到 2.txt。

6 关闭两个文件

7 删除1.txt，将 2.txt 的文件名改为原来 1.txt 的。

文本框 TextBox1

上一条 Button1

下一条 Button2

修改 Button3

Imports System.IO

Public Class Form1

    Dim currIndex As Integer = 0

    Dim s2 As List(Of String) = New List(Of String)

    Dim s As String

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        s = File.ReadAllText(Application.StartupPath & "\txt.txt")

        Dim s1 As String() = s.Split("@")

        For i As Integer = 0 To s1.Length - 1

            If s1(i).Trim() <> "" Then

                s2.Add("@" & s1(i))

            End If

        Next

        TextBox1.Text = s2(0)

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        currIndex = currIndex + 1

        If currIndex > s2.Count - 1 Then

            MsgBox("已经是最后条了")

            Return

        End If

        TextBox1.Text = s2(currIndex)

    End Sub

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

        currIndex = currIndex - 1

        If currIndex < 0 Then

            MsgBox("已经是第一条了")

            Return

        End If

        TextBox1.Text = s2(currIndex)

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

        s2(currIndex) = TextBox1.Text

        s = ""

        For i As Integer = 0 To s2.Count - 1

            s &= s2(i)

        Next

        File.WriteAllText(Application.StartupPath & "\txt.txt", s)

    End Sub

End Class

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