Tip: Detecting a HMODULE/HINSTANCE Handle Within the Module You're Running In

Environment: VC++, DLLs

Most DLL developers have faced the challenge of detecting a HMODULE/HINSTANCE handle within the module you're running in. It may be a difficult task if you wrote the DLL without a DLLMain() function or you are unaware of its name. For example:

Your DLL was built without ATL/MFC, so the DLLMain() function exists, but it's hidden from you code and you cannot access the hinstDLL parameter. You do not know the DLL's real file name because it could be renamed by everyone, so GetModuleHandle() is not for you.

This small code can help you solve this problem:

#if _MSC_VER >= 1300    // for VC 7.0
  // from ATL 7.0 sources
  #ifndef _delayimp_h
  extern "C" IMAGE_DOS_HEADER __ImageBase;
  #endif
#endif

HMODULE GetCurrentModule()
{
#if _MSC_VER < 1300    // earlier than .NET compiler (VC 6.0)

  // Here's a trick that will get you the handle of the module
  // you're running in without any a-priori knowledge:
  // http://www.dotnet247.com/247reference/msgs/13/65259.aspx

  MEMORY_BASIC_INFORMATION mbi;
  static int dummy;
  VirtualQuery( &dummy, &mbi, sizeof(mbi) );

  return reinterpret_cast<HMODULE>(mbi.AllocationBase);

#else    // VC 7.0

  // from ATL 7.0 sources

  return reinterpret_cast<HMODULE>(&__ImageBase);
#endif
}


Comments

  • Good tip indeed! Man, You did it.

    Posted by Legacy on 07/23/2003 12:00am

    Originally posted by: Jeff Zhang

    applaude!

    Reply
  • Posted by Legacy on 07/21/2003 12:00am

    Originally posted by:

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: October 29, 2014 @ 11:00 a.m. ET / 8:00 a.m. PT Are you interested in building a cognitive application using the power of IBM Watson? Need a platform that provides speed and ease for rapidly deploying this application? Join Chris Madison, Watson Solution Architect, as he walks through the process of building a Watson powered application on IBM Bluemix. Chris will talk about the new Watson Services just released on IBM bluemix, but more importantly he will do a step by step cognitive …

  • In support of their business continuity and disaster recovery plans, many midsized companies endeavor to avoid putting all their eggs in one basket. Understanding the critical role of last-mile connectivity and always available Internet access for their enterprises, savvy firms utilize redundant connections from multiple service providers. Despite the good intentions, their Internet connectivity risk may still be in a single basket. That is because internet service providers (ISPs) and competitive local …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds