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How do you create a Win32 window from Console Application?

Started by tom_mai78101 Aug 8, 2011 at 3:28 PM 8 replies 41k views
Original Post
tom_mai78101
tom_mai78101
I have seen a few notable programs which can create windows from console applications. For instance, MCEdit (Minecraft World Editor), it first executes a console, then creates a window.

If I were to guess how it is called, it first goes through main(), then does something, then initializes and do CreateWindow().

How do you create a window without using WinMain() as the entry point? And what are the advantages to doing such things? (Like MCEdit, which is truly popular)
Serapth
Serapth
Pretty much like normal. Create a console app ( /SUBSYSTEM:CONSOLE ), then:



#include <iostream>
#include <windows.h>

long __stdcall WindowProcedure( HWND window, unsigned int msg, WPARAM wp, LPARAM lp )
{
switch(msg)
{
case WM_DESTROY:
std::cout << "\ndestroying window\n" ;
PostQuitMessage(0) ;
return 0L ;
case WM_LBUTTONDOWN:
std::cout << "\nmouse left button down at (" << LOWORD(lp)
<< ',' << HIWORD(lp) << ")\n" ;
// fall thru
default:
std::cout << '.' ;
return DefWindowProc( window, msg, wp, lp ) ;
}
}

int main()
{
std::cout << "hello world!\n" ;
const char* const myclass = "myclass" ;
WNDCLASSEX wndclass = { sizeof(WNDCLASSEX), CS_DBLCLKS, WindowProcedure,
0, 0, GetModuleHandle(0), LoadIcon(0,IDI_APPLICATION),
LoadCursor(0,IDC_ARROW), HBRUSH(COLOR_WINDOW+1),
0, myclass, LoadIcon(0,IDI_APPLICATION) } ;
if( RegisterClassEx(&wndclass) )
{
HWND window = CreateWindowEx( 0, myclass, "title",
WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT, 0, 0, GetModuleHandle(0), 0 ) ;
if(window)
{
ShowWindow( window, SW_SHOWDEFAULT ) ;
MSG msg ;
while( GetMessage( &msg, 0, 0, 0 ) ) DispatchMessage(&msg) ;
}
}
}


FYI, not my code, I pasted from here.
ryan20fun
ryan20fun
they could have attached a Console Window to a Win32 App.
Never say Never, Because Never comes too soon. - ryan20fun

Disclaimer: Each post of mine is intended as an attempt of helping and/or bringing some meaningfull insight to the topic at hand. Due to my nature, my good intentions will not always be plainly visible. I apologise in advance and assure you I mean no harm and do not intend to insult anyone.
yewbie
yewbie

they could have attached a Console Window to a Win32 App.


That's what I do on my app's.
cmasupra
cmasupra
In CodeBlocks, there is an option for whether you want the console window to show up. I don't remember where it is, though.
My indie games
21st Century Moose
21st Century Moose
Not relevant to the question, but worth noting that the sample Serapth posted suffers from a common GetMessage bug, and will go into an infinite loop if an error occurs:

If there is an error, the return value is -1.[/quote]

Beware if you're copy/pasting it.
Direct3D has need of instancing, but we do not. We have plenty of glVertexAttrib calls. 
adeyblue
adeyblue

Not relevant to the question, but worth noting that the sample Serapth posted suffers from a common GetMessage bug, and will go into an infinite loop if an error occurs:

If there is an error, the return value is -1.


Beware if you're copy/pasting it.
[/quote]

Nobody takes it into account because it's nigh-on impossible for it to return -1
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BrianJensen
BrianJensen

[quote name='mhagain' timestamp='1312825087' post='4846275']
Not relevant to the question, but worth noting that the sample Serapth posted suffers from a common GetMessage bug, and will go into an infinite loop if an error occurs:

If there is an error, the return value is -1.


Beware if you're copy/pasting it.
[/quote]

Nobody takes it into account because it's nigh-on impossible for it to return -1
[/quote]

Still not a good idea to use known buggy code no matter how difficult it is to reproduce the result.
21st Century Moose
21st Century Moose

[quote name='adeyblue' timestamp='1312829896' post='4846304']
[quote name='mhagain' timestamp='1312825087' post='4846275']
Not relevant to the question, but worth noting that the sample Serapth posted suffers from a common GetMessage bug, and will go into an infinite loop if an error occurs:

If there is an error, the return value is -1.


Beware if you're copy/pasting it.
[/quote]

Nobody takes it into account because it's nigh-on impossible for it to return -1
[/quote]

Still not a good idea to use known buggy code no matter how difficult it is to reproduce the result.
[/quote]

Plus we don't know what way it's going to behave on future vesions of Windows. We're essentially relying on an implementation detail that could change - the contract for GetMessage guarantees that you will get -1 if there is an error and gives two examples which could generate such an error. That is all. So we're relying on GetMessage to always behave the way it currently does with regard to the unlikelihood of it returning an error, despite the fact that this unlikelihood isn't specified as part of it's contract. Better to just follow the documentation instead (and as a bonus you get to contribute to helping keep hacky compatibility cruft out of Windows).
Direct3D has need of instancing, but we do not. We have plenty of glVertexAttrib calls. 
tom_mai78101
tom_mai78101
I didn't realize how simple that is, to make a window from console.

I guess this solves my problem. Thanks!

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