Re: Use DLL for get Windows Message?

From:

David Wilkinson <no-reply@effisols.com>

Newsgroups:

microsoft.public.vc.language

Date:

Fri, 30 Mar 2007 06:34:08 -0500

Message-ID:

<OI1elbrcHHA.3408@TK2MSFTNGP03.phx.gbl>

leslie eldrige wrote:

Hello NG,

I used a DLL for some WINAPI function's, which I haven't in my language. So
I want to control the menu from my application and I created a DLL function
who give me a window message event. So I just call my DLL function (from my
application) and get a user event, but it doesn't work :(

What's wrong with this code? I hope somebody can help me.

Thanks

__declspec ( dllexport ) DWORD GetMessage(LPSTR pReturn)
{
    MSG msg;
    LPSTR lpstrString="";

    GetMessage(&msg, NULL, 0, 0);

    TranslateMessage( &msg );
    DispatchMessage( &msg );

    switch( msg.message )
    {
    case WM_COMMAND:
        sprintf(lpstrString, "%i", LOWORD(msg.wParam));
        return(DWORD)lpstrString;
        break;
                default:
                               return(DWORD)"";
    }
}

les

les:

In addition to what Ulrich said, you are trying to return a pointer to a
local variable in your function (a big no-no, because it will go out of
scope). And you are not using your pReturn parameter.

You should make sure in yor caller that the string pReturn is long
enough, and sprintf into that. Use your return value just to indicate
success (WM_COMMAND) or failure (not WM_COMMAND). Get rid of the local
variable lpstrString.

You may also need to look into stdcall if you are interfacing to another
language.

David Wilkinson