程序代码：

'聲明INI读写API函數
    Public Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" _
        (ByVal lpApplicationName As String, _
        ByVal lpKeyName As String, _
        ByVal lpDefault As String, _
        ByVal lpReturnedString As String, _
        ByVal nSize As Int32, _
        ByVal lpFileName As String) As Int32
    Public Declare Function WritePrivateProfileString Lib "kernel32" Alias "WritePrivateProfileStringA" _
        (ByVal lpApplicationName As String, _
        ByVal lpKeyName As String, _
        ByVal lpString As String, _
        ByVal lpFileName As String) As Int32
' 用法：
    '读取INI
    Public Function GetINI( _
        ByVal Section As String, _
        ByVal AppName As String, _
        ByVal lpDefault As String, _
        ByVal FileName As String) As String
        Dim Str As String = ""
        Str = LSet(Str, 256)
        GetPrivateProfileString(Section, AppName, lpDefault, Str, Len(Str), FileName)
        Return Microsoft.VisualBasic.Left(Str, InStr(Str, Chr(0)) - 1)
    End Function
    '写入INI 
    Public Function WriteINI( _
    ByVal section As String, _
    ByVal appName As String, _
    ByVal lpDefault As String, _
    ByVal fileName As String) As Long
        WriteINI = WritePrivateProfileString(section, appName, lpDefault, fileName)
    End Function

程序代码：

    '用法示例
    'config.ini文件内容
    '[服务器]
    'IP=192.168.0.250
    '[映射盘符]
    '盘符=Y:

        '判断读是否读取到取配置文件信息,并读取IP信息
        If GetINI("服务器", "IP", "", Application.StartupPath & "\config.ini") = "" Or _
           GetINI("映射盘符", "盘符", "", Application.StartupPath & "\config.ini") = "" Then
            MsgBox("配置文件错误，请进去设置界面进行设置！！！", , "国智网络")
        Else
            ReadIP = GetINI("服务器", "IP", "", Application.StartupPath & "\config.ini") 
        End If

        '写入IP到配置文件
        Dim write1 As Long
        write1 = WriteINI("服务器", "IP", "192.168.0.251", Application.StartupPath & "\config.ini")