Listing 1. Basic Hello World Program

#include <windows.h>

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInst,
                                 HINSTANCE hPrevInst,
                                 PSTR szCmdLine,
                                 int iCmdShow) {
   static TCHAR szAppName[] = TEXT("HelloWin");
   HWND hwnd;
   MSG msg;
   WNDCLASS wndclass;
   wndclass.style = CS_HREDRAW | CS_VREDRAW;
   wndclass.lpfnWndProc = WndProc;
   wndclass.cbClsExtra = 0;
   wndclass.cbWndExtra = 0;
   wndclass.hInstance = hInst;
   wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
   wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
   wndclass.hbrBackground =
(HBRUSH) GetStockObject(WHITE_BRUSH);
   wndclass.lpszMenuName = NULL;
   wndclass.lpszClassName = szAppName;
   if (!RegisterClass(&wndclass)) {
      MessageBox(NULL,
             TEXT("This program requires Windows NT."));
      return 0;
   }
   hwnd = CreateWindow(szAppName,
                       TEXT("The Hello Program"),
                       WS_OVERLAPPEDWINDOW,
                       CW_USEDEFAULT,
                       CW_USEDEFAULT,
                       CW_USEDEFAULT,
                       CW_USEDEFAULT,
                       NULL,
                       NULL,
                       hInst,
                       NULL);
   ShowWindow(hwnd, iCmdShow);
   UpdateWindow(hwnd);
   while (GetMessage(&msg, NULL, 0, 0)) {
      TranslateMessage(&msg);
      DispatchMessage(&msg);
   }
   return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,
                         UINT message,
                         WPARAM wParam,
                         LPARAM lParam) {
   HDC hdc;
   PAINTSTRUCT ps;
   RECT rect;
   switch(message) {
      case WM_CREATE:
         return 0;
      case WM_PAINT:
         hdc = BeginPaint(hwnd, &ps);
         GetClientRect(hwnd, &rect);
         DrawText(hdc,
                  TEXT("Hello, Windows!"),
                  -1, &rect,
             DT_SINGLELINE | DT_CENTER | DT_VCENTER);
         EndPaint(hwnd, &ps);
         return 0;
      case WM_DESTROY:
         PostQuitMessage(0);
         return 0;
   }
   return DefWindowProc(hwnd, message, wParam, lParam);
}