Why doesn't this work?

[Devil Panther]

Why doesn't the BROWSE dialog appear?

                     OPENFILENAME file_data;

                     file_data.lStructSize = 50;
                     file_data.hwndOwner = hwnd;
                     file_data.hInstance = hInst;
                     file_data.lpstrFilter = NULL;
                     file_data.lpstrCustomFilter = NULL;
                     file_data.nMaxCustFilter = 40;
                     file_data.nFilterIndex = NULL;
                     file_data.lpstrFile = NULL;
                     file_data.nMaxFile = 256;
                     file_data.lpstrFileTitle = NULL;
                     file_data.nMaxFileTitle = NULL;
                     file_data.lpstrInitialDir = NULL;
                     file_data.lpstrTitle = NULL;
                     file_data.Flags = OFN_ALLOWMULTISELECT;
                     file_data.nFileOffset = NULL;
                     file_data.nFileExtension = NULL;
                     file_data.lpstrDefExt = NULL;
                     file_data.lCustData = NULL;
                     file_data.lpfnHook = NULL;
                     file_data.lpTemplateName = NULL;

                     GetOpenFileName(&file_data);
                     MessageBox(hwnd, file_data.lpstrFile, "the file", 0);

[sbrothy]

You should always check return codes. If GetOpenFileName returns FALSE you can obtain error information through:

DWORD CommDlgExtendedError(VOID).

It look suspicous that you set lStructSize to 50. Are you sure that

sizeof(OPENFILENAME) == 50

?

[Andreas Masur]

Well...there are several errors in your code...

file_data.lStructSize = 50;

As already mentioned...this flag should be set in the following way:

Windows NT 4.0: In an application that is compiled with WINVER and _WIN32_WINNT >= 0x0500, use OPENFILENAME_SIZE_VERSION_400 for this member.

Windows 2000/XP: Use sizeof (OPENFILENAME) for this parameter.

file_data.hInstance = hInst;

You are setting an instance handle, however, this member is ignored as long as neither the 'OFN_ENABLETEMPLATEHANDLE' nor the 'OFN_ENBALETEMPLATE' flag is set within the 'Flags' member which is not the case in your example...

file_data.lpstrCustomFilter = NULL;
file_data.nMaxCustFilter = 40;

With the two lines you are specifying that 'lpstrCustomFilter' points to an allocated memory buffer of 40 bytes which is not the case...this member gets ignored.

file_data.lpstrFile = NULL;
file_data.nMaxFile = 256;

With the two lines you are specifying that 'lpstrFile' points to an allocated memory buffer of 256 bytes which is not the case...

MessageBox(hwnd, file_data.lpstrFile, "the file", 0);

With this line you are trying to display the selected filename. However, as I mentioned before you did not supply a valid buffer to the member 'lpstrFile' which you are trying to dereference now. This most-likely will crash your application immediately...

[Devil Panther]

Can anyone please give me an example?

[Andreas Masur]

Originally posted by Devil Panther
Can anyone please give me an example?

char         szExtBuffer[MAX_PATH] = "";
OPENFILENAME ofn;

strcpy(szExtBuffer, "*.txt; *.log");

ofn.lStructSize       = sizeof(ofn);
ofn.hwndOwner         = 0;
ofn.hInstance         = 0;
ofn.lpstrFilter       = 0;
ofn.lpstrCustomFilter = 0;
ofn.nMaxCustFilter    = 0;
ofn.nFilterIndex      = 0;
ofn.lpstrFile         = szExtBuffer;
ofn.nMaxFile          = MAX_PATH;
ofn.lpstrFileTitle    = 0;
ofn.nMaxFileTitle     = 0;
ofn.lpstrInitialDir   = 0;
ofn.lpstrTitle        = "Open file";
ofn.Flags             = 0;
ofn.nFileOffset       = 0;
ofn.nFileExtension    = 0;
ofn.lpstrDefExt       = 0;
ofn.lCustData         = 0;
ofn.lpfnHook          = 0;
ofn.lpTemplateName    = 0;

// Open dialog
if(::GetOpenFileName(&ofn) == FALSE)
  [COLOR=#008800]// Cancel pressed

[Devil Panther]

****... it fails, and doesn't show any dialog box... why???

btw, I'm using borland C++ 5.5.

[Paul McKenzie]

The following works correctly. Also, this should work on any Windows compiler.

#include <windows.h>
#include <stdio.h>

int main()
{
   char         szExtBuffer[MAX_PATH] = "";
   OPENFILENAME ofn;
   strcpy(szExtBuffer, "*.txt; *.log");
   memset(&ofn, 0, sizeof(ofn));
   ofn.lStructSize       = sizeof(ofn);
   ofn.lpstrFile         = szExtBuffer;
   ofn.nMaxFile          = MAX_PATH;
   ofn.lpstrTitle        = "Open file";

   // Open dialog
   if(::GetOpenFileName(&ofn) == FALSE)
   {
   }
   return 0;
}

Compiles cleanly, and displays the File open dialog.

Regards,

Paul McKenzie

[Devil Panther]

It does not show me anything...