文本编辑器问题（新手）
/*-------------------------------------- TYPER.C -- Typing Program (c) Charles Petzold, 1998 --------------------------------------*/ #include <windows.h>#define BUFFER(x,y) *(pBuffer + y * cxBuffer + x)LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow){ static TCHAR szAppName[] = TEXT ("Typer") ; 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 ("This program requires Windows NT!"), szAppName, MB_ICONERROR) ; return 0 ; } hwnd = CreateWindow (szAppName, TEXT ("Typing Program"), 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 DWORD dwCharSet = DEFAULT_CHARSET ; static int cxChar, cyChar, cxClient, cyClient, cxBuffer, cyBuffer, xCaret, yCaret ; static TCHAR * pBuffer = NULL ; HDC hdc ; int x, y, i ; PAINTSTRUCT ps ; TEXTMETRIC tm ; switch (message) { case WM_INPUTLANGCHANGE: dwCharSet = wParam ; // fall through case WM_CREATE: hdc = GetDC (hwnd) ; // SelectObject (hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, // dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; GetTextMetrics (hdc, &tm) ; cxChar = tm.tmAveCharWidth ; cyChar = tm.tmHeight ; DeleteObject (SelectObject (hdc, GetStockObject (SYSTEM_FONT))) ; ReleaseDC (hwnd, hdc) ; // fall through case WM_SIZE: // obtain window size in pixels if (message == WM_SIZE) { cxClient = LOWORD (lParam) ; cyClient = HIWORD (lParam) ; } // calculate window size in characters cxBuffer = max (1, cxClient / cxChar) ; cyBuffer = max (1, cyClient / cyChar) ; // allocate memory for buffer and clear it if (pBuffer != NULL) free (pBuffer) ; [color=#FF0000] pBuffer = (TCHAR *) malloc (cxBuffer * cyBuffer * sizeof (TCHAR)) ; for (y = 0 ; y < cyBuffer ; y++) for (x = 0 ; x < cxBuffer ; x++) BUFFER(x,y) = ' ' ;[/color] // set caret to upper left corner xCaret = 0 ; yCaret = 0 ; if (hwnd == GetFocus ()) SetCaretPos (xCaret * cxChar, yCaret * cyChar) ; InvalidateRect (hwnd, NULL, TRUE) ; return 0 ; case WM_SETFOCUS: // create and show the caret CreateCaret (hwnd, NULL, cxChar, cyChar) ; SetCaretPos (xCaret * cxChar, yCaret * cyChar) ; ShowCaret (hwnd) ; return 0 ; case WM_KILLFOCUS: // hide and destroy the caret HideCaret (hwnd) ; DestroyCaret () ; return 0 ; case WM_KEYDOWN: switch (wParam) { case VK_HOME: xCaret = 0 ; break ; case VK_END: xCaret = cxBuffer - 1 ; break ; case VK_PRIOR: yCaret = 0 ; break ; case VK_NEXT: yCaret = cyBuffer - 1 ; break ; case VK_LEFT: xCaret = max (xCaret - 1, 0) ; break ; case VK_RIGHT: xCaret = min (xCaret + 1, cxBuffer - 1) ; break ; case VK_UP: yCaret = max (yCaret - 1, 0) ; break ; case VK_DOWN: yCaret = min (yCaret + 1, cyBuffer - 1) ; break ; case VK_DELETE: for (x = xCaret ; x < cxBuffer - 1 ; x++) BUFFER (x, yCaret) = BUFFER (x + 1, yCaret) ; BUFFER (cxBuffer - 1, yCaret) = ' ' ; HideCaret (hwnd) ; hdc = GetDC (hwnd) ; SelectObject (hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; TextOut (hdc, xCaret * cxChar, yCaret * cyChar, & BUFFER (xCaret, yCaret), cxBuffer - xCaret) ; DeleteObject (SelectObject (hdc, GetStockObject (SYSTEM_FONT))) ; ReleaseDC (hwnd, hdc) ; ShowCaret (hwnd) ; break ; } SetCaretPos (xCaret * cxChar, yCaret * cyChar) ; return 0 ; case WM_CHAR: for (i = 0 ; i < (int) LOWORD (lParam) ; i++) { switch (wParam) { case '\b': // backspace if (xCaret > 0) { xCaret-- ; SendMessage (hwnd, WM_KEYDOWN, VK_DELETE, 1) ; } break ; case '\t': // tab do { SendMessage (hwnd, WM_CHAR, ' ', 1) ; } while (xCaret % 8 != 0) ; break ; case '\n': // line feed if (++yCaret == cyBuffer) yCaret = 0 ; break ; case '\r': // carriage return xCaret = 0 ; if (++yCaret == cyBuffer) yCaret = 0 ; break ; case '\x1B': // escape for (y = 0 ; y < cyBuffer ; y++) for (x = 0 ; x < cxBuffer ; x++) BUFFER (x, y) = ' ' ; xCaret = 0 ; yCaret = 0 ; InvalidateRect (hwnd, NULL, FALSE) ; break ; default: // character codes BUFFER (xCaret, yCaret) = (TCHAR) wParam ; HideCaret (hwnd) ; hdc = GetDC (hwnd) ; SelectObject (hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; TextOut (hdc, xCaret * cxChar, yCaret * cyChar, & BUFFER (xCaret, yCaret), 1) ; DeleteObject ( SelectObject (hdc, GetStockObject (SYSTEM_FONT))) ; ReleaseDC (hwnd, hdc) ; ShowCaret (hwnd) ; if (++xCaret == cxBuffer) { xCaret = 0 ; if (++yCaret == cyBuffer) yCaret = 0 ; } break ; } } SetCaretPos (xCaret * cxChar, yCaret * cyChar) ; return 0 ; case WM_PAINT: hdc = BeginPaint (hwnd, &ps) ; SelectObject (hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; HideCaret(hwnd); MoveToEx(hdc,100,100,NULL); LineTo(hdc,20,400); ShowCaret(hwnd); for (y = 0 ; y < cyBuffer ; y++) TextOut (hdc, 0, y * cyChar, & BUFFER(0,y), cxBuffer) ; DeleteObject (SelectObject (hdc, GetStockObject (SYSTEM_FONT))) ; EndPaint (hwnd, &ps) ; return 0 ; case WM_DESTROY: PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ;}