Window messages in windows application with no window

Question

I have an application that I want to run in the background with no visible windows or consoles. To accomplish this, I create a windows application but I do not create a window.

Answer 1

Do not bother with creating a dummy window, there is a much easier way to handle shutdown / exit control events in a windowless application. To do this, you use a little known Win API function called: SetConsoleCtrlHandler (...)

Here is an example of how to use the Control Handler:

#include  

// You can fill-in your own behavior, this is just an example handler that
//   covers most of the most common events.
BOOL
ControlHandler (DWORD dwControlEvent) 
{ 
  switch (dwControlEvent) 
  { 
    // User wants to shutdown
    case CTRL_SHUTDOWN_EVENT: 
      return FALSE; 

    // User wants to logoff
    case CTRL_LOGOFF_EVENT: 
      return FALSE; 

    // Ctrl + C
    case CTRL_C_EVENT:
      return TRUE;

    // User wants to exit the "normal" way 
    case CTRL_CLOSE_EVENT:
      return TRUE;

    // Everything else, just ignore it...
    default:
      return FALSE; 
  } 
} 

int
main (void) 
{ 
  // Set the control handler so the app will be notified upon any special
  //   termination event.
  SetConsoleCtrlHandler ((PHANDLER_ROUTINE) ControlHandler, TRUE); 

  //
  // Main Loop Here ...
  //

  return 0;
}

I had to learn about this a couple of years ago because some middle-ware was not properly cleaning up its resources when my console application was terminated with Ctrl + C. I discovered it by accident when I was looking at the stack trace. It is worth mentioning that this supercedes the standard signal handler for events like Ctrl + C.

By the way, even though it is called a "Console Control Handler," it works perfectly fine in applications that use WinMain (...) instead of main (...).