Ciao a tutti! Devo sviluppare un prgramma GUI con c++ e ho iniziato a stendere il codiece per le cose più semplici, ma mi si è già presentato un problma.
Ho questi file di resource:
resource.rc
codice:
#include "resource.h"
#include "windows.h"

ID_MENU MENU
BEGIN
     POPUP "&File"
     BEGIN
          MENUITEM "&Apri...", ID_APRI
          MENUITEM "&Esci", ID_ESCI
     END
     POPUP "&Informazioni"
     BEGIN
          MENUITEM "A&bout", ID_ABOUT
     END
END

IDD_ABOUT DIALOG DISCARDABLE  0, 0, 239, 66
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Informazioni su..."
FONT 8, "MS Sans Serif"
BEGIN
    DEFPUSHBUTTON   "&OK",IDOK,174,18,50,14
    GROUPBOX        "Informazioni su...",-1,7,7,225,52
    CTEXT           "Un esempio di Finestre",-1,16,18,144,33
END
e resource.h
codice:
#define ID_MENU 101
#define ID_DIALOG_ABOUT 102

#define ID_APRI 1001
#define ID_ESCI 1002
#define ID_ABOUT 1011
e fin qui tutto bene, il problema si presenta quando tento di aprire il dialog: ecco il codice
codice:
#include <windows.h>
#include "resource.h"

LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
BOOL CALLBACK AboutDlgProc(HWND, UINT, WPARAM,LPARAM);

char *szClassName = "NomeClasse";

int WINAPI WinMain (HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = MAKEINTRESOURCE(ID_MENU);                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_MENU;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        exit(EXIT_FAILURE);

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "TitoloApp",       /* Title Text */
           WS_OVERLAPPED|WS_MINIMIZEBOX|WS_CAPTION|WS_SYSMENU, /* Windows style */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           544,                 /* The programs width */
           375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

    /* Make the window visible on the screen */
    ShowWindow (hwnd, SW_SHOW);

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_DESTROY:
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        case WM_COMMAND:
            switch(wParam)
            {
                case ID_ESCI:
                     PostQuitMessage (0);
                     break;
                case ID_ABOUT:
                     int ret = DialogBox(GetModuleHandle(NULL), MAKEINTRESOURCE(ID_DIALOG_ABOUT), hwnd, AboutDlgProc);
                     if(ret == -1)
                     MessageBox(NULL,"Impossibile caricare file","Errore",NULL);
                     break;
            }
             break;
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

BOOL CALLBACK AboutDlgProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
     switch(message)
     {
        case WM_INITDIALOG:
             return true;
             break;
        case WM_COMMAND:
             switch(LOWORD(wParam))
             {
                case IDOK:
                    EndDialog(hwnd, IDOK);
                break;
             }
             break;
        default:
             return false;
     }
     return true;
}
Ho notato che la funzione DialogBox ritorna -1, ma non capisco dove sia l'errore... Ogni suggerimento è ben accetto