LoadLibrary

[Scott Turchin]

Think I got a grasp on this, I took working code and converted this for a sample, anyone find anything wrong with this?

Scott

#Compile Exe
#Dim All
#Option Version4
#Register None
#Include "Win32api.inc"


Declare Function ProcessMyFunction(DLvar1 As Long, var2 As String) As Long
Declare Function MyFunction Lib "MY.DLL"(var1 As Long, var2 As String) As Long

Function PbMain() As Long
Local wUser As String
wUser = "UserName:"


'These variables are ONLY samples, don't even have to be there
'If they don't change, set them in ProcessMyFunction as local variables
'vs passing them through the "Thunk" type DLL.
If IsTrue ProcessMyFunction(SizeOf(wUser), wUser) Then
   MsgBox "It worked!!", %MB_ICONINFORMATION,"Wahoooo!"
Else
   MsgBox "It didn't work, sorry charlie..", %MB_ICONINFORMATION,":("
End If
End Function
'===================================================================================
Function ProcessMyFunction(var1 As Long, var2 As String) As Long
Local hLib As Long
Local procAddr As Dword

hLib = LoadLibrary("MY.DLL")
'Where "MYFUNCTION" is the function name in the DLL, IN UPPER CASE!
procaddr = GetProcAddress(hLib,"MYFUNCTION")
If ProcAddr = %NULL Then
    'Failed to find the function. Do Msgbox or error out
    MsgBox "Failed to find function MYFUNCTION in MY.DLL" , %MB_ICONSTOP, "Error, failed to find procedure"
    Exit Function ' Function is already false here
Else
  'Found the function, process it now
   Call Dword ProcAddr Using MyFunction(var1,var2) 'Adjust function input accordingly, may have ot pass variables
   Function = %TRUE 'or a return from the function itself, suggestions?
End If
End Function

-------------
Scott
mailto:[email protected][email protected]</A>

[DorianDarby]

Hi Scott,

I've been working on a project in PB which allows the use of "Plug in" tools, in the form of other DLL's.

I use GetProcAddress() and LoadLibrary like you have, but with one major difference:

If your sample below was changed to look like how I do it, it would be:

Declare Function MyFunction (var1 As Long, var2 As String) As Long


Notice how the lib "my.dll" is missing. The Declare Function merely tells PB how the parameters are specified, and the name of the function could be anything, it does not need to match the name of the function in my.dll

Once you have the proc address of "MYFUNCTION" (as in your code), you then use the CALL DWORD line and use the above declaration.

e.g.

Declare Function Anything (var1 As Long, var2 As String) As Long

...
...
procaddr = GetProcAddress(hLib,"MYFUNCTION")
CALL DWORD ProcAddr Using Anything(var1,var2) TO lFunctionResult

As you can see, the declared function name is irrelevant, but the parameters are.

The return value of the function call will be placed into lFunctionResult.

Hope this helps....

Dorian.

------------------


[This message has been edited by DorianDarby (edited April 04, 2000).]

[Scott Turchin]

Thanks and Hi
Question is, if you run the application and the DLL is not in the path or is not on the hard drive, with my method the program should continue, testing now...

Yes, this here works perfectly now!! I just tested this and if the DLL was missing (I renamed it) the program would say "DLL Not found, missing or corrupt" etc....
And when the DLL was there it created a shortcut on my desktop.....


Also, I don't have the source to the DLL in case anyone is wondering...people ask me all the time Wish I did, but I don't...

Declare Function CreateShortcut _  Alias "CREATESHORTCUT"_
                 (sPath As String, _               ' Path of the file the shortcut refers too.
                  sArguments As String, _          ' Program command line args.
                  sLocation As String, _           ' Destination path for the shortcut.
                  sWorkingDir As String, _         ' Working directory.
                  ByVal nCmdShow As Long) As Long


Function CreateTheShortCut() As Long

    Local procAddr  As Dword
    Local hLib      As Long
    Local IsNt      As Long
    Local sLocation As String          'For placing icon

    If Instr(Environ$("OS"),"Windows_NT") Then IsNT = 1

    If IsNT Then
        sLocation = Environ$("SystemRoot") & "\Profiles\All Users\Desktop\" & g_sWinLog & " For Windows NT.LNK"
    Else
        sLocation = Environ$("windir") & "\Desktop\" & g_sWinLog & " For Windows 98.LNK"
    End If
    
    hLib = LoadLibrary("SHORTCUT.DLL")
    If hLib Then
        procAddr = GetProcAddress(hLib, "CREATESHORTCUT")
        If ProcAddr = %NULL Then
            MsgBox "Could not find function ""CreateShortcut"" in SHORTCUT.DLL",%MB_ICONSTOP,g_szCCS
            'But continue anyway
        Else
            Call Dword ProcAddr Using CreateShortCut(_
            g_sWinLogFilePath & g_sWinLogEXE,"", sLocation, g_sWinLogFilePath,2)' To g_Result
            g_Result = FreeLibrary(hLib)
'            If IsTrue Exist("Shortcut.dll") Then Kill "Shortcut.dll"
        End If
    Else
        MsgBox "Unable to open Shortcut.dll, file may be corrupt or missing",48, g_szMINE
    End If

End Function

------------------
Scott
mailto:[email protected][email protected]</A>