Question

I have written a program which triggers a relay switch on a serial port. The relay is closed for 10ms, after which the program closes. However, the program insists on running in a small command prompt window. I would like the program to run without stealing focus; either by running in the background or, even better, without opening a window at all.

Here is the complete program:

#include <windows.h>

//Initialise Windows module
int WINAPI WinMain (HINSTANCE hThisInstance, HINSTANCE hPrevInstance,
LPSTR lpszArgument, int nFunsterStil)
{
 //Define the serial port precedure
 HANDLE hSerial;

 //Open the port
 hSerial = CreateFile("COM1",GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);

 //Switch on relay
 EscapeCommFunction(hSerial, SETDTR);

 //Wait 10ms
 Sleep(10);

 //Switch off relay
 EscapeCommFunction(hSerial, CLRDTR);

 //Close the port
 CloseHandle(hSerial);

 //End with error code 0
 return 0;
}

What must I change in order to prevent it running in a window?

Answer 1

Try adding

#pragma comment(linker, "/SUBSYSTEM:WINDOWS")

If that does not work try to hide the window manually:

HWND hWnd = GetConsoleWindow();
ShowWindow( hWnd, SW_HIDE );