No cout from wxWidget application, but with Eclipse it works fine - c++

Question

my wxWidget Application does not make any std::cout << "xyz" ... on a windows console (Windows XP) when it is startet from a console by e.g.: "call MyApplication.exe". It will produce no output at all. The Application instead rises correctly and works fine. All Buttons and Widgets on the Frame have their functions working.
When I run my application from Eclipse, it produces its outputs as it should be to Eclipse' console.
So, why i can't see any output on windows console? What do i have to activate?

Answer 1

I've always been curious about this, so I followed the links provided in Bo Persson's answer and pieced together some code. To use it, just define a UseConsole object in main.
UseConsole.h:
class UseConsole
{
public:
UseConsole();
~UseConsole();
private:
bool m_good;
};
UseConsole.cpp:
#include <windows.h>
#include <stdio.h>
#include <fcntl.h>
#include <io.h>
#include <iostream>
#include <fstream>
#include "UseConsole.h"
// The following function is taken nearly verbatim from
// http://www.halcyon.com/~ast/dload/guicon.htm
void RedirectIOToConsole()
{
int hConHandle;
long lStdHandle;
FILE *fp;
// redirect unbuffered STDOUT to the console
lStdHandle = (long)GetStdHandle(STD_OUTPUT_HANDLE);
hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
fp = _fdopen( hConHandle, "w" );
*stdout = *fp;
setvbuf( stdout, NULL, _IONBF, 0 );
// redirect unbuffered STDIN to the console
lStdHandle = (long)GetStdHandle(STD_INPUT_HANDLE);
hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
fp = _fdopen( hConHandle, "r" );
*stdin = *fp;
setvbuf( stdin, NULL, _IONBF, 0 );
// redirect unbuffered STDERR to the console
lStdHandle = (long)GetStdHandle(STD_ERROR_HANDLE);
hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
fp = _fdopen( hConHandle, "w" );
*stderr = *fp;
setvbuf( stderr, NULL, _IONBF, 0 );
// make cout, wcout, cin, wcin, wcerr, cerr, wclog and clog
// point to console as well
std::ios::sync_with_stdio();
}
UseConsole::UseConsole()
{
m_good = !!AttachConsole(ATTACH_PARENT_PROCESS);
if (m_good)
RedirectIOToConsole();
}
UseConsole::~UseConsole()
{
if (m_good)
FreeConsole();
}

Answer 2

A windowed application by default doesn't have a console. You can create one if you like to have one anyway.
See the answers to this question:
Visual C++ Enable Console
When running in an IDE, the IDE often does that for you.
If you already have a console window open, you can alternatively attach to the parent process' console using AttachConsole(ATTACH_PARENT_PROCESS).
http://msdn.microsoft.com/en-us/library/ms681952(v=vs.85).aspx