win32程序基础

// Foward declarations of functions included in this code module:
ATOM   MyRegisterClass(HINSTANCE hInstance);
BOOL   InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
  // TODO: Place code here.
 MSG msg;
 HACCEL hAccelTable;

 // Initialize global strings
 LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
 LoadString(hInstance, IDC_B, szWindowClass, MAX_LOADSTRING);
 MyRegisterClass(hInstance);

 // Perform application initialization:
 if (!InitInstance (hInstance, nCmdShow))
 {
  return FALSE;
 }

 hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_B);

 // Main message loop:   ////消息循环探测
 while (GetMessage(&msg, NULL, 0, 0))
 {
  if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
  {
   TranslateMessage(&msg);//传换键盘消息
   DispatchMessage(&msg);//传送消息在user module的协助下
  }
 }

 return msg.wParam;
}
//窗口函数      分派消息时,是靠user Module的协助,找到对应的窗口函数

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
 int wmId, wmEvent;
 PAINTSTRUCT ps;
 HDC hdc;
 TCHAR szHello[MAX_LOADSTRING];
 LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);

 switch (message)
 {
  case WM_COMMAND:
   wmId    = LOWORD(wParam);
   wmEvent = HIWORD(wParam);
   // Parse the menu selections:
   switch (wmId)
   {
    case IDM_ABOUT:
       DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
       break;
    case IDM_EXIT:
       DestroyWindow(hWnd);
       break;
    default:
       return DefWindowProc(hWnd, message, wParam, lParam);
   }
   break;
  case WM_PAINT:
   hdc = BeginPaint(hWnd, &ps);
   // TODO: Add any drawing code here...
   RECT rt;
   GetClientRect(hWnd, &rt);
   DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER);
   EndPaint(hWnd, &ps);
   break;
  case WM_DESTROY:
   PostQuitMessage(0);
   break;
  default:
   return DefWindowProc(hWnd, message, wParam, lParam);  //默认的窗口处理函数
   }
   return 0;
}