Create window console inside main win32 window

Question

I have a win32 application that need to open a console like the games when tilde is pressed. I tought that the best solution is to use the CreateWindow function. Is this right?

Answer 1

The solutions here won't work because newer versions of the Windows SDK define the FILE structure by:

#ifndef _FILE_DEFINED
    #define _FILE_DEFINED
    typedef struct _iobuf
    {
        void* _Placeholder;
    } FILE;
#endif

When trying to overwrite the stdin/out FILE structures with the = operator, only one pointer will be copied. To copy the whole FILE struct, you have to define the FILE structure before your windows.h include:

#ifndef _FILE_DEFINED
struct _iobuf {
        char *_ptr;
        int   _cnt;
        char *_base;
        int   _flag;
        int   _file;
        int   _charbuf;
        int   _bufsiz;
        char *_tmpfname;
        };
typedef struct _iobuf FILE;
#define _FILE_DEFINED
#endif

#include <Windows.h>

If this is somehow not possible for you, you can still define your own FILE structure as FILE_COMPLETE and use this codesnippet:

#include <Windows.h>
#include <io.h>
#include <fcntl.h>

AllocConsole();
SetConsoleTitleA("ConsoleTitle");
typedef struct { char* _ptr; int _cnt; char* _base; int _flag; int _file; int _charbuf; int _bufsiz; char* _tmpfname; } FILE_COMPLETE;
*(FILE_COMPLETE*)stdout = *(FILE_COMPLETE*)_fdopen(_open_osfhandle((long)GetStdHandle(STD_OUTPUT_HANDLE), _O_TEXT), "w");
*(FILE_COMPLETE*)stderr = *(FILE_COMPLETE*)_fdopen(_open_osfhandle((long)GetStdHandle(STD_ERROR_HANDLE), _O_TEXT), "w");
*(FILE_COMPLETE*)stdin = *(FILE_COMPLETE*)_fdopen(_open_osfhandle((long)GetStdHandle(STD_INPUT_HANDLE), _O_TEXT), "r");
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);
setvbuf(stdin, NULL, _IONBF, 0);

Answer 2

This is some pretty old code, haven't even really looked over it. Hopefully it's what you need. If you just need a very simple one you can also just make a call to AllocConsole();

void DevConsole::Create(){

  CONSOLE_SCREEN_BUFFER_INFO consoleInfo;
  int consoleHandleR, consoleHandleW ;
  long stdioHandle;
  FILE *fptr;

  AllocConsole();
  std::wstring strW = L"Dev Console";
  SetConsoleTitle( strW.c_str() );

  EnableMenuItem(GetSystemMenu(GetConsoleWindow(), FALSE), SC_CLOSE , MF_GRAYED);
  DrawMenuBar(GetConsoleWindow());

  GetConsoleScreenBufferInfo( GetStdHandle(STD_OUTPUT_HANDLE), &consoleInfo );

  stdioHandle = (long)GetStdHandle( STD_INPUT_HANDLE );
  consoleHandleR = _open_osfhandle( stdioHandle, _O_TEXT );
  fptr = _fdopen( consoleHandleR, "r" );
  *stdin = *fptr;
  setvbuf( stdin, NULL, _IONBF, 0 );

  stdioHandle = (long) GetStdHandle( STD_OUTPUT_HANDLE );
  consoleHandleW = _open_osfhandle( stdioHandle, _O_TEXT );
  fptr = _fdopen( consoleHandleW, "w" );
  *stdout = *fptr;
  setvbuf( stdout, NULL, _IONBF, 0 );

  stdioHandle = (long)GetStdHandle( STD_ERROR_HANDLE );
  *stderr = *fptr;
  setvbuf( stderr, NULL, _IONBF, 0 );

}

Answer 3

It's often tempting to use a console window in your app (using AllocConsole), but it is definitely NOT a standard reusable Windows control. It has a lot of special behaviors and features which make it unique from a typical window.

For this reason, I would agree with your instinct, against using a true 'Console' window. Make your own window with a text editor in it, as you would develop any other UI component like a HUD.

Whether you should use CreateWindow is hard to say: how are you doing the rest of your GUI? DirectX? GDI? Some toolkit? Are you using other standard windows controls?

Answer 4

I found this little tutorial / code samples useful. http://www.halcyon.com/~ast/dload/guicon.htm

It creates a console and redirects STD_IN and STD_OUT to the console. So you can easily use std::cin and std::cout etc streams.