This is the code as attempted so far:
#include <windows.h>
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppname[] = TEXT ("win0") ;
WNDCLASS wndclass ;
MSG msg ;
HWND hwnd ;
wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.cbWndExtra = 0 ;
wndclass.cbClsExtra = 0 ;
wndclass.lpfnWndProc = WndProc ;
wndclass.lpszClassName = szAppname ;
wndclass.lpszMenuName = NULL ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hInstance = hInstance ;
if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("Register fail"), szAppname, 0) ;
return 0 ;
}
hwnd = CreateWindow ( szAppname,
TEXT ("mywin"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
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)
{
static int cxClient, cyClient, Left, Top, Right, Down ;
PAINTSTRUCT ps ;
HDC hdc ;
RECT rect ;
Right = 20 ; Down = 20 ;
switch (message)
{
case WM_SIZE :
cxClient = LOWORD (lParam) ;
cyClient = HIWORD (lParam) ;
return 0 ;
case WM_PAINT :
hdc = BeginPaint (hwnd, &ps) ;
SetRect (&rect, Left, Top, Right, Down) ;
FillRect (hdc, &rect, CreateSolidBrush (RGB (100, 100, 100))) ;
EndPaint (hwnd, &ps) ;
return 0 ;
case WM_KEYDOWN :
InvalidateRect (hwnd, &rect, TRUE) ;
switch (wParam)
{
case VK_UP :
if (Top - 20 < 0)
{
Top = 0 ;
Down = 20 ;
}
else
{
Top -= 20 ;
Down -= 20 ;
}
SendMessage (hwnd, WM_PAINT, wParam, lParam) ;
break ;
case VK_DOWN :
if (Down + 20 > cyClient)
{
Down = cyClient ;
Top = Down - 20 ;
}
else
{
Down += 20 ;
Top += 20 ;
}SendMessage (hwnd, WM_PAINT, wParam, lParam) ;
break ;
case VK_LEFT :
if (Left - 20 < 0)
{
Left = 0 ;
Right = 20 ;
}
else
{
Left -= 20 ;
Right -= 20 ;
}SendMessage (hwnd, WM_PAINT, wParam, lParam) ;
break ;
case VK_RIGHT :
if (Right + 20 > cxClient)
{
Right = cxClient ;
Left = Right - 20 ;
}
else
{
Right += 20 ;
Left += 20 ;
}SendMessage (hwnd, WM_PAINT, wParam, lParam) ;
break ;
default :
break ;
}
return 0 ;
case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam);
}
I considered that I didn't deal the message well, so I can't control it.
