程序7-3所示的CHECKER2程序，除了包括键盘接口外，和CHECKER1是一样的，您可以使用左、右、上和下方向键在25个矩形之间移动光标。Home键把光标移动到矩形的左上角， End键把光标移动到矩形的右下角。Spacebar和Enter键都能切换X标记。
程序7-3 CHECKER2
CHECKER2.C /*---------------------------------------------------------------------------- CHECKER2.C -- Mouse Hit-Test Demo Program No. 2 (c) Charles Petzold, 1998 ----------------------------------------------------------------------------*/ #include <windows.h> #define DIVISIONS 5 LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT ("Checker2") ; HWND hwnd ; MSG msg ; WNDCLASS wndclass ; wndclass.style = CS_HREDRAW | CS_VREDRAW ; wndclass.lpfnWndProc = WndProc ; 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 ; if (!RegisterClass (&wndclass)) { MessageBox ( NULL, TEXT ("Program requires Windows NT!"), szAppName, MB_ICONERROR) ; return 0 ; } hwnd = CreateWindow ( szAppName, TEXT ("Checker2 Mouse Hit-Test Demo"), 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 BOOL fState[DIVISIONS][DIVISIONS] ; static int cxBlock, cyBlock ; HDC hdc ; int x, y ; PAINTSTRUCT ps ; POINT point ; RECT rect ; switch (message) { case WM_SIZE : cxBlock = LOWORD (lParam) / DIVISIONS ; cyBlock = HIWORD (lParam) / DIVISIONS ; return 0 ; case WM_SETFOCUS : ShowCursor (TRUE) ; return 0 ; case WM_KILLFOCUS : ShowCursor (FALSE) ; return 0 ; case WM_KEYDOWN : GetCursorPos (&point) ; ScreenToClient (hwnd, &point) ; x = max (0, min (DIVISIONS - 1, point.x / cxBlock)) ; y = max (0, min (DIVISIONS - 1, point.y / cyBlock)) ; switch (wParam) { case VK_UP : y-- ; break ; case VK_DOWN : y++ ; break ; case VK_LEFT : x-- ; break ; case VK_RIGHT : x++ ; break ; case VK_HOME : x = y = 0 ; break ; case VK_END : x = y = DIVISIONS - 1 ; break ; case VK_RETURN : case VK_SPACE : SendMessage (hwnd, WM_LBUTTONDOWN, MK_LBUTTON, MAKELONG (x * cxBlock, y * cyBlock)) ; break ; } x = (x + DIVISIONS) % DIVISIONS ; y = (y + DIVISIONS) % DIVISIONS ; point.x = x * cxBlock + cxBlock / 2 ; point.y = y * cyBlock + cyBlock / 2 ; ClientToScreen (hwnd, &point) ; SetCursorPos (point.x, point.y) ; return 0 ; case WM_LBUTTONDOWN : x = LOWORD (lParam) / cxBlock ; y = HIWORD (lParam) / cyBlock ; if (x < DIVISIONS && y < DIVISIONS) { fState[x][y] ^= 1 ; rect.left = x * cxBlock ; rect.top = y * cyBlock ; rect.right = (x + 1) * cxBlock ; rect.bottom = (y + 1) * cyBlock ; InvalidateRect (hwnd, &rect, FALSE) ; } else MessageBeep (0) ; return 0 ; case WM_PAINT : hdc = BeginPaint (hwnd, &ps) ; for (x = 0 ; x < DIVISIONS ; x++) for (y = 0 ; y < DIVISIONS ; y++) { Rectangle (hdc, x * cxBlock, y * cyBlock, (x + 1) * cxBlock, (y + 1) * cyBlock) ; if (fState [x][y]) { MoveToEx (hdc, x *cxBlock, y *cyBlock, NULL) ; LineTo (hdc, (x+1)*cxBlock, (y+1)*cyBlock) ; MoveToEx (hdc, x *cxBlock, (y+1)*cyBlock, NULL) ; LineTo (hdc, (x+1)*cxBlock, y *cyBlock) ; } } EndPaint (hwnd, &ps) ; return 0 ; case WM_DESTROY : PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ; }