Windows Programming: Hello, World is displayed in the middle of the window.

1 # include <windows. h> 2 3 lresult callback MyWndProc (HWND hwnd, // handle to window 4 UINT uMsg, // message identifier 5 WPARAM wParam, // first message parameter 6 LPARAM lParam // second message parameter 7); 8 9 int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) 10 {11 WNDCLASS wnd; 12 HWND hwnd; 13 MSG msg; 14 wnd. style = CS_HREDRAW | CS_VREDRAW ;// The horizontal or vertical change windows are repainted and associated with the WM_PAINT message of MyWndProc 15 wnd. lpfnWndProc = MyWndProc; 16 wnd. cbClsExtra = 0; 17 wnd. cbWndExtra = 0; 18 wnd. hIcon = LoadIcon (NULL, IDI_APPLICATION); 19 wnd. hCursor = LoadCursor (NULL, IDC_ARROW); 20 wnd. hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH); 21 wnd. lpszMenuName = NULL; 22 wnd. lpszClassName = "HelloClass"; // window class ID, used in the first parameter 23 wnd of CreateWindow. hInstance = hInstance; 24 if (! RegisterClass (& wnd) 25 {26 MessageBox (NULL, TEXT ("cannot create window"), TEXT ("ERROR"), MB_ OK | MB_ICONERROR); 27 return 0; 28} 29 30 hwnd = CreateWindow ("HelloClass", TEXT ("Hello"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, NULL, NULL, hInstance, NULL ); // The second parameter is window Title 31 ShowWindow (hwnd, nShowCmd); 32 while (GetMessage (& msg, NULL, 0, 0) 33 {34 TranslateMessage (& msg ); 35 DispatchMe Ssage (& msg); 36} 37 return 0; 38} 39 40 lresult callback MyWndProc (HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) 41 {42 HDC hdc; // define the device environment handle 43 PAINTSTRUCT ps; // draw structure 44 RECT rect; // rectangular structure 45 switch (uMsg) 46 {47 case WM_PAINT: 48 {49 hdc = BeginPaint (hwnd, & ps); 50 GetClientRect (hwnd, & rect); 51 DrawText (hdc, TEXT ("Hello, World! "),-1, & rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER); 52 EndPaint (hwnd, & ps); 53} 54 break; 55 case WM_DESTROY: 56 PostQuitMessage (0 ); 57 return 0; 58} 59 60 return DefWindowProc (hwnd, uMsg, wParam, lParam); 61}