Următorul exemplu implementează mult de funcționalitate de un simplu procesor de umplere zona client o fereastră cu un control de editare cu mai multe linii. Sistemul efectuează automat word wrap operațiuni pentru acest control de editare și, de asemenea, mânere prelucrării pe bara de defilare verticală (creat de specificarea ES_AUTOVSCROLL în apelul la funcția de CreateWindow ). Mesajul WM_COMMAND procesează elementele de meniu; acestea permit utilizatorului să anulați acțiunea anterioară, tăiate sau copia selecții din clipboard, lipiți text din clipboard și șterge selecția curentă.
LONG APIENTRY MainWndProc(
HWND hwnd, // window handle
UINT message, // type of message
WPARAM wParam, // additional information
LPARAM lParam) // additional information
{
static HWND hwndEdit;
CHAR lpszTrouble[] = "When in the Course of human Events "
"it becomes necessary for one People "
"to dissolve the Political Bands which "
"have connected them with another, and "
"to assume among the Powers of the "
"Earth, the separate and equal Station "
"to which the Laws of Nature and of "
"Nature's God entitle them, a decent "
"Respect to the Opinions of Mankind "
"requires that they should declare the "
"causes which impel them to the "
"Separation. ";
switch (message)
{
case WM_CREATE:
hwndEdit = CreateWindow(
"EDIT", // predefined class
NULL, // no window title
WS_CHILD | WS_VISIBLE | WS_VSCROLL |
ES_LEFT | ES_MULTILINE | ES_AUTOVSCROLL,
0, 0, 0, 0, // set size in WM_SIZE message
hwnd, // parent window
(HMENU) ID_EDITCHILD, // edit control ID
(HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE),
NULL); // pointer not needed
// Add text to the window.
SendMessage(hwndEdit, WM_SETTEXT, 0,
(LPARAM) lpszTrouble);
return 0;
case WM_COMMAND:
switch (wParam)
{
case IDM_EDUNDO:
// Send WM_UNDO only if there is something
// to be undone.
if (SendMessage(hwndEdit, EM_CANUNDO, 0, 0))
SendMessage(hwndEdit, WM_UNDO, 0, 0);
else
{
MessageBox(hwndEdit,
"Nothing to undo.",
"Undo notification", MB_OK);
}
break;
case IDM_EDCUT:
SendMessage(hwndEdit, WM_CUT, 0, 0);
break;
case IDM_EDCOPY:
SendMessage(hwndEdit, WM_COPY, 0, 0);
break;
case IDM_EDPASTE:
SendMessage(hwndEdit, WM_PASTE, 0, 0);
break;
case IDM_EDDEL:
SendMessage(hwndEdit, WM_CLEAR, 0, 0);
break;
case IDM_PASSWORD:
DialogBox(hinst, // current instance
"PassBox", // resource to use
hwnd, // parent handle
(DLGPROC) PassProc);
break;
case IDM_WRAP:
SendMessage(hwndEdit,
EM_SETWORDBREAKPROC,
(WPARAM) 0,
(LPARAM) (EDITWORDBREAKPROC) WordBreakProc);
SendMessage(hwndEdit,
EM_FMTLINES,
(WPARAM) TRUE,
(LPARAM) 0);
SendMessage(hwndEdit,
EM_SETSEL,
0, -1); // select all text
SendMessage(hwndEdit, WM_CUT, 0, 0);
SendMessage(hwndEdit, WM_PASTE, 0, 0);
break;
case IDM_ABOUT:
DialogBox(hinst, // current instance
"AboutBox", // resource to use
hwnd, // parent handle
(DLGPROC) About);
break;
default:
return DefWindowProc(hwnd, message, wParam, lParam);
}
break;
case WM_SETFOCUS:
SetFocus(hwndEdit);
return 0;
case WM_SIZE:
// Make the edit control the size of the window's
// client area.
MoveWindow(hwndEdit,
0, 0, // starting x- and y-coordinates
LOWORD(lParam), // width of client area
HIWORD(lParam), // height of client area
TRUE); // repaint window
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
default:
return DefWindowProc(hwnd, message, wParam, lParam);
}
return NULL;
}