int ReplaceDLLBitmapResource( LPCWSTR pszDLLFile, WORD dwResourceID, LPCWSTR pszBitmapFile )
{
CFile f;
CFileException e;
USES_CONVERSION;
if( ! f.Open( W2T(pszBitmapFile), CFile::modeRead, &e ) )
return -1;
BYTE buffer[8];
DWORD dwRead;
dwRead = f.Read( buffer, 2 );
if( buffer[0] != 'B' || buffer[1] != 'M' )
{
f.Close();
return -2;
}
LONG biWidth;
f.Seek( 18, CFile::begin );
dwRead = f.Read( buffer, sizeof(LONG) );
biWidth = buffer[1]*256 + buffer[0];
LONG biHeight;
f.Seek( 22, CFile::begin );
dwRead = f.Read( buffer, sizeof(LONG) );
biHeight = buffer[1]*256 + buffer[0];
// Bitmap height can be negative too...
WORD biBitCount;
f.Seek( 28, CFile::begin );
dwRead = f.Read( buffer, sizeof(LONG) );
biBitCount = buffer[1]*256 + buffer[0];
DWORD dwSize;
f.Seek( 2, CFile::begin );
dwRead = f.Read( buffer, sizeof(DWORD) );
dwSize = buffer[3]*256*256*256 + buffer[2]*256*256 + buffer[1]*256 + buffer[0];
dwSize -= 14;
unsigned char* bitmap = (unsigned char*)malloc( dwSize );
if( !bitmap )
{
f.Close();
return -3;
}
f.Seek( 14, CFile::begin );
dwRead = f.Read( bitmap, dwSize );
if( dwRead != dwSize )
{
f.Close();
return -4;
}
f.Close();
// Open DLL file
HANDLE hUpdateRes = BeginUpdateResource( W2T(pszDLLFile), FALSE );
if( hUpdateRes == NULL )
return -5; // Could not open file for writing
// Modify resource to DLL file
if( ! UpdateResource( hUpdateRes, // update resource handle
RT_BITMAP, // change bitmap resource
MAKEINTRESOURCE(dwResourceID), // resource name
MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), // neutral language
bitmap, // ptr to resource info
dwSize ) // size of resource info.
)
return -6; // Could not add resource
// Write changes to DLL file and then close it
if( ! EndUpdateResource( hUpdateRes, FALSE ) )
return -7; //Could not write changes to file
free( bitmap );
return 0;
}
Updating Resources
The following example copies a dialog box resource from one executable file, Hand.exe, to another, Foot.exe, by following these steps:
Use the LoadLibrary function to load the executable file Hand.exe.
Use the FindResource and LoadResource functions to locate and load the dialog box resource.
Use the LockResource function to retrieve a pointer to the dialog box resource data.
Use the BeginUpdateResource function to open an update handle to Foot.exe.
Use the UpdateResource function to copy the dialog box resource from Hand.exe to Foot.exe.
Use the EndUpdateResource function to complete the update.
The following code implements these steps.
HRSRC hResLoad; // handle to loaded resource
HANDLE hExe; // handle to existing .EXE file
HRSRC hRes; // handle/ptr. to res. info. in hExe
HANDLE hUpdateRes; // update resource handle
char *lpResLock; // pointer to resource data
BOOL result;
// Load the .EXE file that contains the dialog box you want to copy.
hExe = LoadLibrary("hand.exe");
if (hExe == NULL)
{
ErrorHandler("Could not load exe.");
}
// Locate the dialog box resource in the .EXE file.
hRes = FindResource(hExe, "AboutBox", RT_DIALOG);
if (hRes == NULL)
{
ErrorHandler("Could not locate dialog box.");
}
// Load the dialog box into global memory.
hResLoad = LoadResource(hExe, hRes);
if (hResLoad == NULL)
{
ErrorHandler("Could not load dialog box.");
}
// Lock the dialog box into global memory.
lpResLock = LockResource(hResLoad);
if (lpResLock == NULL)
{
ErrorHandler("Could not lock dialog box.");
}
// Open the file to which you want to add the dialog box resource.
hUpdateRes = BeginUpdateResource("foot.exe", FALSE);
if (hUpdateRes == NULL)
{
ErrorHandler("Could not open file for writing.");
}
// Add the dialog box resource to the update list.
result = UpdateResource(hUpdateRes, // update resource handle
RT_DIALOG, // change dialog box resource
"AboutBox", // dialog box name
MAKELANGID(LANG_NEUTRAL, SUBLANG_NEUTRAL), // neutral language
lpResLock, // ptr to resource info
SizeofResource(hExe, hRes)); // size of resource info.
if (result == FALSE)
{
ErrorHandler("Could not add resource.");
}
// Write changes to FOOT.EXE and then close it.
if (!EndUpdateResource(hUpdateRes, FALSE))
{
ErrorHandler("Could not write changes to file.");
}
// Clean up.
if (!FreeLibrary(hExe))
{
ErrorHandler("Could not free executable.");
}