最经典的SDK程序结构 HelloWin

/*------------------------------------------------------------
   HELLOWIN.C -- Displays "Hello, Windows 98!" in client area
                 (c) Charles Petzold, 1998
  ------------------------------------------------------------*/

#include <windows.h>

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     // 第零步，提前定义变量
     static TCHAR szAppName[] = TEXT ("HelloWin") ; // 窗口的类名
     HWND         hwnd ; // 窗口创建后得到的句柄
     MSG          msg ;  // 消息循环用的消息变量（就一个）
     // 第一步，定义窗口类
     WNDCLASS     wndclass ;

     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ; // 重要属性：窗口函数（回调函数）
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ; // 重要属性：窗口类名称

     // 第二步，注册窗口类
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"), 
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }

     // 第三步，创建窗口类
     hwnd = CreateWindow (szAppName,                  // window class name
                          TEXT ("The Hello Program"), // window caption
                          WS_OVERLAPPEDWINDOW,        // window style
                          CW_USEDEFAULT,              // initial x position
                          CW_USEDEFAULT,              // initial y position
                          CW_USEDEFAULT,              // initial x size
                          CW_USEDEFAULT,              // initial y size
                          NULL,                       // parent window handle
                          NULL,                       // window menu handle
                          hInstance,                  // program instance handle
                          NULL) ;                     // creation parameters

     // 第四步，显示窗口
     ShowWindow (hwnd, iCmdShow) ; 
     // 第五步，刷新窗口
     UpdateWindow (hwnd) ;

     // 第六步，消息循环
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     // 最后一步，将最后一个消息的wParam参数返回给main函数当作函数结果
     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:
          PlaySound (TEXT ("hellowin.wav"), NULL, SND_FILENAME | SND_ASYNC) ; // API
          return 0 ;
          
     case WM_PAINT:
          hdc = BeginPaint (hwnd, &ps) ; // API
          
          GetClientRect (hwnd, &rect) ; // API
          
          DrawText (hdc, TEXT ("Hello, Windows 98!"), -1, &rect,
                    DT_SINGLELINE | DT_CENTER | DT_VCENTER) ; // API
          
          EndPaint (hwnd, &ps) ; // API
          return 0 ;
          
     case WM_DESTROY:
          PostQuitMessage (0) ; // API
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ; // API
}