MSG msg;
while(GetMessage(&msg, NULL, 0, 0) > 0){
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}
			

// stdafx.h
#pragma once

#include <atlbase.h>
#include <atlapp.h>
extern CAppModule _Module;
#include <atlwin.h>

#include <atlcrack.h> // WTLメッセージクラッカーを使うため
			

// MainWindow.h
#pragma once

class CMainWindow : public CWindowImpl<CMainWindow>
{
public:
    DECLARE_WND_CLASS(_T("Hello"));

    // メッセージマップ
    BEGIN_MSG_MAP(CMainWindow)
        MSG_WM_PAINT(OnPaint)
        MSG_WM_DESTROY(OnDestroy)
    END_MSG_MAP()

    void OnPaint(CDCHandle /*dc*/){
        PAINTSTRUCT ps;
        HDC hDC = BeginPaint(&ps);
        RECT rect;
        GetClientRect(&rect);
        DrawText(hDC, _T("Hello, ATL/WTL"),
            -1, &rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        EndPaint(&ps);
    }

    void OnDestroy(){
        PostQuitMessage(0);
    }
};
			

// SampleProject.cpp
#include "stdafx.h"
#include "MainWindow.h"

CAppModule _Module;

int APIENTRY _tWinMain(HINSTANCE hInstance, 
                       HINSTANCE hPrevInstance, 
                       LPTSTR    lpCmdLine, 
                       int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    _Module.Init(NULL, hInstance);

    CMessageLoop theLoop;
    _Module.AddMessageLoop(&theLoop);

    CMainWindow wnd;
    wnd.Create(NULL, CWindow::rcDefault,
        _T("Hello, ATL/WTL"), WS_OVERLAPPEDWINDOW | WS_VISIBLE);

    int nRet = theLoop.Run();

    _Module.RemoveMessageLoop();

    _Module.Term();

    return nRet;
}