How To Get the CLSID and ProgID of a CoClass from the Type Library in OCX, DLL, and EXE Files (286340)

MORE INFORMATION

Sample Code

#include "stdafx.h"
#include <stdio.h>
#include <windows.h>
#include <comdef.h>
void DisplayError(HRESULT hr);
void Cleanup();
ITypeLib *pTypeLib = NULL;
ITypeInfo *pTypeInfo = NULL;
TYPEATTR *pTypeAttr = NULL;
int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow)
{
	_bstr_t str;
	HRESULT hr;
	WCHAR* pwszProgID = NULL;
        // This assumes that the .ocx file contains the type library information.
        // If it does not, we can replace the .ocx file with the .tlb file.
	hr = LoadTypeLib(L"f:\\winnt\\system32\\comdlg32.ocx",&pTypeLib);
	if ( FAILED(hr)) 
	{
           Cleanup(); // Release the Interface pointers.
	   DisplayError(hr); // Display the error that corresponds to the HRESULT.
           return 0;
	}
	UINT iCount = pTypeLib->GetTypeInfoCount(); 
	// There may be multiple types that are defined in a type library. 
         // Let us iterate through them to find the CoClasses that are defined.
	for (int i=0; i < iCount ; i++) 
            {
	       // Obtain ITypeInfo interface.
               if (FAILED(hr = (pTypeLib->GetTypeInfo(i, &pTypeInfo))))
                 {
                    DisplayError(hr);
                    Cleanup();
                    return 0;
                 }
	       // Obtain TYPEATTR structure.
               if (FAILED(hr = (pTypeInfo->GetTypeAttr(&pTypeAttr))))
                 {
                    DisplayError(hr);
                    Cleanup();
                    return 0;
                 }
	        // Check if this is a CoClass.
		if (TKIND_COCLASS == pTypeAttr->typekind)
		  // pTypeAttr->guid contains the CLSID of the CoClass.
		  if (!FAILED(hr =  (ProgIDFromCLSID(pTypeAttr->guid,&pwszProgID))))
		     {
			str = pwszProgID;
			// Display the ProgID.
			::MessageBox(NULL,str,str,MB_OK);
			CoTaskMemFree(pwszProgID);
		     }
		pTypeInfo->ReleaseTypeAttr(pTypeAttr);
		pTypeInfo->Release();
			
             }

	pTypeLib->Release();
	pTypeLib = NULL;
	return 0;
}

void DisplayError(HRESULT hr)
{
      LPVOID lpMsgBuf;
      FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | 
		  FORMAT_MESSAGE_FROM_SYSTEM    		  |
		  FORMAT_MESSAGE_IGNORE_INSERTS		  ,
		  NULL,hr, 
                  // Default language.
		  MAKELANGID(LANG_NEUTRAL,  SUBLANG_DEFAULT), 
                  // Process any inserts in lpMsgBuf.
                 (LPTSTR) &lpMsgBuf, 0, NULL );
      char szTemp[100];
      wsprintf(szTemp, "%s\n", lpMsgBuf);
}
void Cleanup()
{
      if (pTypeAttr)
          pTypeInfo->ReleaseTypeAttr(pTypeAttr);

      if (pTypeInfo)
          pTypeInfo->Release();
      pTypeAttr = NULL;
      pTypeInfo = NULL;
}