#include <windows.h>
#include <windowsx.h>
#include <tchar.h>
#include <cstdio>
FILE* fp = NULL;/* BOOL Cls_OnCreate(HWND hwnd, LPCREATESTRUCT lpCreateStruct) */
//#define HANDLE_WM_CREATE(hwnd, wParam, lParam, fn) ((fn)((hwnd), (LPCREATESTRUCT)(lParam)) ? 0L : (LRESULT)-1L)
//#define FORWARD_WM_CREATE(hwnd, lpCreateStruct, fn) (BOOL)(DWORD)(fn)((hwnd), WM_CREATE, 0L, (LPARAM)(LPCREATESTRUCT)(lpCreateStruct))

BOOL fnWndProc_OnCreate(HWND hWnd, LPCREATESTRUCT lpCreateStruct)
{fprintf(fp,"  Entering fnWndProc_OnCreate()\n");fprintf(fp,"    hWnd = %u\n",(unsigned)hWnd);fprintf(fp,"  Leaving fnWndProc_OnCreate()\n\n");/*  MSDN states WM_CREATE should return 0 to continue and -1 for failure *///return FALSE;/*  but the HANDLE_WM_CREATE macro translates return values greater than zero to 0, and the rest to -1. */return TRUE;
}/*  void Cls_OnSize(HWND hwnd, UINT state, int cx, int cy) */
//  #define HANDLE_WM_SIZE(hwnd, wParam, lParam, fn) ((fn)((hwnd), (UINT)(wParam), (int)(short)LOWORD(lParam), (int)(short)HIWORD(lParam)), 0L)
//  #define FORWARD_WM_SIZE(hwnd, state, cx, cy, fn)  (void)(fn)((hwnd), WM_SIZE, (WPARAM)(UINT)(state), MAKELPARAM((cx), (cy)))void fnWndProc_OnSize(HWND hWnd, UINT state, int cx, int cy)
{fprintf(fp,"  Entering fnWndProc_OnSize()\n");fprintf(fp,"    Width = %d\tHeight = %d\n",cx,cy);fprintf(fp,"  Leaving fnWndProc_OnSize()\n\n");
}/*  void Cls_OnPaint(HWND hwnd) */
//  #define HANDLE_WM_PAINT(hwnd, wParam, lParam, fn) ((fn)(hwnd), 0L)
//  #define FORWARD_WM_PAINT(hwnd, fn) (void)(fn)((hwnd), WM_PAINT, 0L, 0L)void fnWndProc_OnPaint(HWND hWnd)
{PAINTSTRUCT ps;HDC hDC;fprintf(fp,"  Entering fnWndProc_OnPaint()\n");hDC=BeginPaint(hWnd,&ps);fprintf(fp,"    Painting Window!\n");fprintf(fp,"    ps.rcPaint.right  = %d\n",(int)ps.rcPaint.right);fprintf(fp,"    ps.rcPaint.bottom = %d\n",(int)ps.rcPaint.bottom);EndPaint(hWnd,&ps);fprintf(fp,"  Leaving fnWndProc_OnPaint()\n\n");
}/* void Cls_OnClose(HWND hwnd) */
// #define HANDLE_WM_CLOSE(hwnd, wParam, lParam, fn) ((fn)(hwnd), 0L)
// #define FORWARD_WM_CLOSE(hwnd, fn) (void)(fn)((hwnd), WM_CLOSE, 0L, 0L)void fnWndProc_OnClose(HWND hWnd)
{fprintf(fp,"  Entering fnWndProc_OnClose()\n");fprintf(fp,"    hWnd = %u\n",(unsigned)hWnd);DestroyWindow(hWnd);fprintf(fp,"  Leaving fnWndProc_OnClose()\n");
}/* void Cls_OnDestroy(HWND hwnd) */
//  #define HANDLE_WM_DESTROY(hwnd, wParam, lParam, fn)    ((fn)(hwnd), 0L)
//  #define FORWARD_WM_DESTROY(hwnd, fn)   (void)(fn)((hwnd), WM_DESTROY, 0L, 0L)void fnWndProc_OnDestroy(HWND hWnd)
{fprintf(fp,"    Entering fnWndProc_OnDestroy()\n");fprintf(fp,"      hWnd = %u\n",(unsigned)hWnd);PostQuitMessage(0);fprintf(fp,"    Leaving fnWndProc_OnDestroy()\n");
}LRESULT CALLBACK fnWndProc(HWND hwnd, unsigned int msg, WPARAM wParam, LPARAM lParam)
{switch(msg){HANDLE_MSG(hwnd, WM_CREATE,  fnWndProc_OnCreate);HANDLE_MSG(hwnd, WM_SIZE,    fnWndProc_OnSize);HANDLE_MSG(hwnd, WM_PAINT,   fnWndProc_OnPaint);HANDLE_MSG(hwnd, WM_CLOSE,   fnWndProc_OnClose);HANDLE_MSG(hwnd, WM_DESTROY, fnWndProc_OnDestroy);default:return (DefWindowProc(hwnd, msg, wParam, lParam));}
}int WINAPI WinMain(HINSTANCE hIns, HINSTANCE hPrevIns, LPSTR lpszArgument, int nShow)
{TCHAR szClassName[] = _T("Debugging Windows Programs");WNDCLASSEX wc;MSG messages;HWND hWnd;wc.lpszClassName = szClassName;                wc.lpfnWndProc=fnWndProc;wc.cbSize = sizeof(WNDCLASSEX);                wc.style=CS_DBLCLKS;wc.hIcon = LoadIcon(NULL,IDI_APPLICATION);     wc.hInstance=hIns;wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);  wc.hCursor=LoadCursor(NULL,IDC_ARROW);wc.hbrBackground = (HBRUSH)COLOR_BTNSHADOW;    wc.cbWndExtra=0;wc.lpszMenuName = NULL;                        wc.cbClsExtra=0;RegisterClassEx(&wc);fp = fopen("Output.txt","w");fprintf(fp,"Output.txt Opened In WinMain()\n");hWnd = CreateWindowEx(0,szClassName,szClassName,WS_OVERLAPPEDWINDOW,75,75,320,305,HWND_DESKTOP,0,hIns,0);ShowWindow(hWnd,nShow);while(GetMessage(&messages,NULL,0,0)){TranslateMessage(&messages);DispatchMessage(&messages);}fprintf(fp,"Output.txt Closed In WinMain()\n");fclose(fp);return messages.wParam;
}

Output.txt Opened In WinMain()Entering fnWndProc_OnCreate()hWnd = 658154Leaving fnWndProc_OnCreate()Entering fnWndProc_OnSize()Width = 304   Height = 267Leaving fnWndProc_OnSize()Entering fnWndProc_OnPaint()Painting Window!ps.rcPaint.right  = 304ps.rcPaint.bottom = 267Leaving fnWndProc_OnPaint()Entering fnWndProc_OnClose()hWnd = 658154Entering fnWndProc_OnDestroy()hWnd = 658154Leaving fnWndProc_OnDestroy()Leaving fnWndProc_OnClose()
Output.txt Closed In WinMain()