Reading from an INI file

Question

I find it very easy to write to a INI file, but am having some trouble in retrieving the data from an already created INI file.

I am using this function:

    Public Declare Unicode Function GetPrivateProfileString Lib "kernel32" _
    Alias "GetPrivateProfileStringW" (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

If I have an INI file called 'c:\temp\test.ini', with the following data:

[testApp]
KeyName=keyValue
KeyName2=keyValue2

How can I retrieve the values of KeyName and KeyName2?

I have tried this code, with no success:

    Dim strData As String
    GetPrivateProfileString("testApp", "KeyName", "Nothing", strData, Len(strData), "c:\temp\test.ini")
    MsgBox(strData)

Answer 1

Going to the Pinvoke.Net Web site and modifying their example worked, their Function declaration is different.

Modified Example

Imports System.Runtime.InteropServices
Imports System.Text
Module Module1
    Private Declare Auto Function GetPrivateProfileString Lib "kernel32" (ByVal lpAppName As String, _
            ByVal lpKeyName As String, _
            ByVal lpDefault As String, _
            ByVal lpReturnedString As StringBuilder, _
            ByVal nSize As Integer, _
            ByVal lpFileName As String) As Integer

    Sub Main()

        Dim res As Integer
        Dim sb As StringBuilder

        sb = New StringBuilder(500)
        res = GetPrivateProfileString("testApp", "KeyName", "", sb, sb.Capacity, "c:\temp\test.ini")
        Console.WriteLine("GetPrivateProfileStrng returned : " & res.ToString())
        Console.WriteLine("KeyName is : " & sb.ToString())
        Console.ReadLine();

    End Sub
End Module