If you download and install the demo of Barcodesoft Data Matrix font on your
computer, you will find crUFLBCS.dll from
"C:\Program Files\Common Files\Barcodesoft\Fontutil\" folder.

crUFLBCS.dll is a COM object with IDataMatrix interface.
You can find detailed information about this interface from readme.html.

To call the method of this interface from VC++, you can use either Late Binding or Early Binding.
Late binding is used when type information of an object is unavailable at compile time.
Early binding requires the client to get access to the type library before compile.



Late Binding


Your codes run slower than using Early Binding.
However, your codes are supposed to be
version-independent as long as COM interface
and method parameters remain unchanged.

CoInitialize(NULL);
CLSID clsid;
if (FAILED(::CLSIDFromProgID(L"cruflbcs.DataMatrix.1", &clsid)))
return 0;
IDispatch* pIDispatch = NULL;
if (FAILED(::CoCreateInstance(clsid, NULL, CLSCTX_INPROC_SERVER, IID_IDispatch, (void**)&pIDispatch)))
return 0;
LPOLESTR szNameEncode = L"Encode";
DISPID dispid_encode;
HRESULT hr = pIDispatch->GetIDsOfNames(IID_NULL, &szNameEncode, 1, LOCALE_SYSTEM_DEFAULT, &dispid_encode);
CComBSTR bstrResult;
VARIANTARG v[1];
v[0].vt = VT_BSTR; v[0].bstrVal = SysAllocString(L"Barcodesoft Sample");
DISPPARAMS dispParams = { v, NULL, 1, 0 };
VARIANT vResult;
hr = pIDispatch->Invoke( dispid_encode, IID_NULL, GetUserDefaultLCID(), DISPATCH_METHOD,
&dispParams, &vResult, NULL, NULL);
if (FAILED(hr))
return 0;
pIDispatch->Release();
CoUninitialize();

Early Binding


Your codes run faster than using Late Binding.
First, Import type library. Don't forget to call
CoInitialize() before using COM interface.
If you want to use T2OLE macro to convert
LPTSTR into LPOLESTR, you need to call USES_CONVERSION macro first.

#import "cruflbcs.dll"
using namespace cruflBCS;

USES_CONVERSION;
CoInitialize(NULL);
_bstr_t bstrOutput;
char pszToEncode[] = "Barcodesoft Sample";
try
{
cruflBCS::IDataMatrixPtr pBCSDataMatrix(__uuidof(CBCSDataMatrix));
bstrOutput = pBCSDataMatrix->Encode(T2OLE(pszToEncode));
}
catch (const _com_error& e)
{
_tprintf(_T("Error: 0x%08x %s\n"), e.Error(), e.ErrorMessage());
}
CoUninitialize();

Use MFC to Generate Wrapper Class


If you use VC++ 6, press Ctrl + W to start Class Wizard. Then click "Add Class" button, choose "From a type library".
Choose crUFLBCS.dll, then select all Interfaces you want to add wrappers and click OK.

If you use Visual Studio 2003 or above,
1. On the Project menu, select Add Class.
2. Select MFC Class from Typelib from the list of templates.
3. For Add Class from, select Registry.
4. In the list of available type libraries, find crUFLBCS.
5. From the list of interfaces in that type library, select all classes for which you want to add wrappers.
6. Click Finish.

Please don't forget to call OleInitialize(NULL) before using the following code snippet.

CString strOutput;
IDataMatrix *pDataMatrixObj = new IDataMatrix();
if ( pDataMatrixObj->CreateDispatch("cruflbcs.DataMatrix.1")
strOutput = pDataMatrixObj->Encode("Barcodesoft Sample");