Opening a File Dialog from within a class module in vb6

Question

I want to know how can we open a file dialog from withing a class module in vb6. I know how to do in forms, but I have to open it from within a class module.

Answer 1

Have a look at the API below:

Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias _
    "GetOpenFileNameA" (pOpenfilename As OPENFILENAME) As Long

Here's a sample of it in use:

    Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias _
        "GetOpenFileNameA" (pOpenfilename As OPENFILENAME) As Long

    Private Type OPENFILENAME
        lStructSize As Long
        hwndOwner As Long
        hInstance As Long
        lpstrFilter As String
        lpstrCustomFilter As String
        nMaxCustFilter As Long
        nFilterIndex As Long
        lpstrFile As String
        nMaxFile As Long
        lpstrFileTitle As String
        nMaxFileTitle As Long
        lpstrInitialDir As String
        lpstrTitle As String
        flags As Long
        nFileOffset As Integer
        nFileExtension As Integer
        lpstrDefExt As String
        lCustData As Long
        lpfnHook As Long
        lpTemplateName As String
    End Type

    Private Function FileOpenDialog()
        Dim sFilter As String

        OpenFile.lStructSize = Len(OpenFile)
        sFilter = "Text Files (*.txt)" & Chr(0) & "*.TXT" & Chr(0)
        OpenFile.lpstrFilter = sFilter
        OpenFile.nFilterIndex = 1
        OpenFile.lpstrFile = String(257, 0)
        OpenFile.nMaxFile = Len(OpenFile.lpstrFile) - 1
        OpenFile.lpstrFileTitle = OpenFile.lpstrFile
        OpenFile.nMaxFileTitle = OpenFile.nMaxFile
        OpenFile.lpstrInitialDir = "C:\"
        OpenFile.lpstrTitle = "Select File"
        OpenFile.flags = 0

        lReturn = GetOpenFileName(OpenFile)


    End Function

Answer 2

Yes, you can call the API to raise this dialog.

Most of the time though this sort of need stems from a broken paradigm. A Class should not have a UI. When you have a real need for this your Class should probably be a UserControl... and the problem goes away.