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  • Your email address will not be published.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

  • Enterprise endpoint backup can satisfy data collection and preservation requirements in a more streamlined and cost-effective manner than traditional e-discovery methods. Enterprise IT teams face increasing challenges as the amount of valuable data living on endpoints continues to grow. Due to the exploding volume, mobility and compliance requirements of enterprise data, the need to collect and preserve that data for the purpose of e-discovery becomes more critical--and more difficult. Traditionally, …

  • New IT trends to support worker mobility -- such as VDI and BYOD -- are quickly gaining interest and adoption. But just as with any new trend, there are concerns and pitfalls to avoid. Download this paper to learn the most important considerations to keep in mind for your VDI project.

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date