How to show an openfile dialog on windows?

Question

I'm trying to get an openfile dialog to show up on windows CE 6.0 according to msdn it's the same process as in win32, but it doesn't work. I submit for review the interresting part of the code :

#include <windows.h>
#include <commctrl.h>
#include <winuser.h>
#include <stdio.h>
#include <Commdlg.h>

/* Prototypes */
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
HWND create_window(int width, int height) ;
void resize_window(int width, int height) ;

HWND    g_hWindow ;

/* Function to modify the host window size to match the size of the movie. */
void resize_window(int width, int height)
{
   RECT r;
   r.left = r.top = 0;
   r.right = width ;
   r.bottom  = height ;
   AdjustWindowRectEx(&r,WS_BORDER,false,WS_EX_CLIENTEDGE);
   SetWindowPos(g_hWindow, NULL, 0,0,r.right, r.bottom,SWP_NOMOVE|SWP_NOOWNERZORDER|SWP_NOZORDER);
}


HWND create_window(int width, int height)
{
   WNDCLASS wce; // A Window class in Windows CE

   wce.style         = CS_VREDRAW | CS_HREDRAW; 
   wce.lpfnWndProc   = (WNDPROC) WndProc; 
   wce.cbClsExtra    = 0; 
   wce.cbWndExtra    = 0; 
   wce.hInstance     = GetModuleHandle(NULL); 
   wce.hIcon         = LoadIcon((HINSTANCE) NULL, (LPCWSTR)MB_ICONQUESTION);
   wce.hCursor       = LoadCursor((HINSTANCE) NULL, IDC_ARROW); 
   wce.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH); 
   wce.lpszMenuName  = 0;
   wce.lpszClassName = _TEXT("TEST");

   if (!RegisterClass(&wce)) return 0; 

   RECT r;
   r.left = r.top = 0;
   r.right = width ;
   r.bottom  = height ;
   AdjustWindowRectEx(&r,WS_BORDER,false,WS_EX_CLIENTEDGE);

  // Create the window
   g_hWindow = CreateWindowEx(
      0,          // Ex Styles
      WS_BORDER,      // creates a window that has a thin-line border with no title bar
      CW_USEDEFAULT,  // x
      CW_USEDEFAULT,  // y
      r.right-r.left,  // Height
      r.bottom-r.top,  // Width
      NULL,           // Parent Window
      NULL,           // Menu, or windows id if child
      GetModuleHandle(NULL),      // 
      NULL            // Pointer to window specific data
      );

   ShowWindow( g_hWindow, SW_SHOW  ); // make the window visible on the display

   return g_hWindow ;
}

/* 
 * Messaging function call back from Windows CE that is passed as 
 * an argument when the window is created
 */
LRESULT CALLBACK WndProc(HWND   hWnd,
                         UINT   msg,
                         WPARAM wParam,
                         LPARAM lParam ) 
{

   switch( msg ) 
   {
    case WM_ACTIVATEAPP:


            // Invalidate to get new text painted.
        this->Invalidate();
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;   

    case WM_CREATE:
        LPOPENFILENAME opendialog;
        wchar_t szFile[260];


        opendialog = (LPOPENFILENAME) malloc(sizeof (LPOPENFILENAME));
        opendialog->lStructSize = sizeof (LPOPENFILENAME);
        opendialog->hwndOwner = g_hWindow;
        opendialog->hInstance = GetModuleHandle(NULL);
        *szFile = (char_t)_TEXT("\0");
        opendialog->lpstrFile = szFile;
        opendialog->nFilterIndex = 0;
        opendialog->nMaxFile = 256;
        opendialog->lpstrInitialDir = NULL;
        opendialog->Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

        GetOpenFileName(opendialog);


    default:
        return DefWindowProc( hWnd, msg, wParam, lParam);
   } 
   return 0;
}

/* Function to hide (or make visible) the taskbar so that the player has the full display */
void set_display(bool set_full)
{
   HWND hwndTaskbar = ::FindWindow(L"HHTaskBar", NULL);
   if (set_full)
   {
       ::ShowWindow(hwndTaskbar, SW_HIDE); 
   }
   else
   {
       ::ShowWindow(hwndTaskbar, SW_SHOW); 
   }
   g_full_scrn = set_full;
}


int _cdecl WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR argv, int argc )
{

   memset(&g_gfx_context,0,sizeof(g_gfx_context));
   create_window(1, 1); // This is a windows CE specific call.
}

Answer 1

LPOPENFILENAME opendialog;
mb_char_t szFile[260];

opendialog = (LPOPENFILENAME) mb_malloc(sizeof (LPOPENFILENAME));
opendialog->lStructSize = sizeof (LPOPENFILENAME);

You are declaring a pointer to an OPENFILENAME structure here, and allocating memory for it.

You should be able to allocate OPENFILENAME on stack directly, like so:

OPENFILENAME opendialog = {0};
mb_char_t szFile[260] = {0};

opendialog.lStructSize = sizeof (opendialog);
opendialog.hwndOwner = g_hWindow;
opendialog.hInstance = GetModuleHandle(NULL);
opendialog.lpstrFile = szFile;
opendialog.nFilterIndex = 0;
opendialog.nMaxFile = 256;
opendialog.lpstrInitialDir = NULL;
opendialog.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

GetOpenFileName(&opendialog);

Answer 2

Here's a problem:

opendialog->lStructSize = sizeof (LPOPENFILENAME);

That will set the struct size to the size of a pointer, which is 4 in your case. You should have:

opendialog->lStructSize = sizeof (OPENFILENAME);