SendMessage WM_GETTEXT LB_GETTEXT returns nothing

[jsublime]

I have succesfully retrieved the handle of a control (which appears to be a list box) with the following code:

  Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer
    Public Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Integer, ByVal hWnd2 As Integer, ByVal lpsz1 As String, ByVal lpsz2 As String) As Integer
    Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hWnd As Integer, ByVal lpString As String, ByVal cch As Integer) As Integer
    Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hWnd As Integer, ByVal lpClassName As String, ByVal nMaxCount As Integer) As Integer
    Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As String) As Integer

Public Sub main()
        Dim lngParent As Integer
        Dim lngChild As Integer
        Dim lngChild2 As Integer
        Dim lngChild3 As Integer

        Dim cReturn As Long, lParam As Long, parHwnd As Long

'I'm walking down the window tree until I find the control that I need
         lngParent = FindWindow(vbNullString, "xxx- Home (Search)")
          If lngParent <> 0 Then
            ShowWindowInfo(lngParent)
            lngParent = FindWindowEx(lngParent, 0, "MDIClient", vbNullString)
            ShowWindowInfo(lngParent)
            lngParent = FindWindowEx(lngParent, 0, vbNullString, "Home (Search)")
            ShowWindowInfo(lngParent)
            lngParent = FindWindowEx(lngParent, 0, "AfxMDIFrame70", vbNullString)
            ShowWindowInfo(lngParent)
            lngParent = FindWindowEx(lngParent, 0, "AfxFrameOrView70", vbNullString)
            ShowWindowInfo(lngParent)
            lngParent = FindWindowEx(lngParent, 0, "SysTabControl32", vbNullString)
            ShowWindowInfo(lngParent)
            lngParent = FindWindowEx(lngParent, 0, vbNullString, "Home")
            ShowWindowInfo(lngParent)
            lngChild = FindWindowEx(lngParent, 0, "GXWND", vbNullString)
            ShowWindowInfo(lngChild)
            lngChild2 = FindWindowEx(lngParent, lngChild, "GXWND", vbNullString)
            ShowWindowInfo(lngChild2)
            lngChild3 = FindWindowEx(lngParent, lngChild2, "GXWND", vbNullString)
            ShowWindowInfo(lngChild3)

End if
End sub

Private Sub ShowWindowInfo(ByVal hWnd As Integer)

        Dim lRet As Integer
        Dim buffer As String
        Dim message As String
        Dim j As Integer
        Dim wtext As String


        Const WM_GETTEXT = &HD
        Const LB_GETCOUNT = &H18B


        wtext = Space(256)
        j = SendMessage(hWnd, WM_GETTEXT, 255, wtext)
        wtext = Left(wtext, j)

        message = "Window handle: " & hWnd & vbCrLf

        buffer = Space(256)
        lRet = GetWindowText(hWnd, buffer, 256&)
        message = message & "Window text: " & Left$(wtext, j) & "  also: " & lRet & vbCrLf

        buffer = Space(256)
        lRet = GetClassName(hWnd, buffer, 256&)
        message = message & "Class name: " & Left$(buffer, lRet) & vbCrLf

        Debug.Print(message)

    End Sub

The control I'm accessing appears to be a listbox but I monitored the messages using Window Detective and all I'm seeing is WM type messages when I click on the various elements. I was expecting WM_GETTEXT to return the string for the currently selected item, but it has always been empty. Any suggestions?

[Andrewpeter]

I do this as following:

1. hWndList is ListBox handle, you find it yourself.
2. Declare two messages: LB_GETCOUNT and LB_GETTEXT.
3. The code to get text of the current item:

Dim index As Integer
Dim textBuff As String
textBuff = Space(255)
index = SendMessage(hWndList, LB_GETCOUNT, 0, 0)
SendMessage hWndList, LB_GETTEXT, i, textBuff
MsgBox textBuff