Changing the Color of an Edit Control

• Microsoft Windows Software Development Kit (SDK) for Windows versions 3.1 and 3.0

SUMMARY

The source code fragment below demonstrates how to paint the foreground and background of a single-line edit control in an application developed for the Microsoft Windows graphical environment. It creates a window that contains one single-line edit control and paints the edit control cyan on blue.

Windows sends the WM_CTLCOLOR message to the parent of an edit control before the control is painted. If desired, the parent window, usually a dialog box procedure, can process this message and change the text and background colors of the control.

NOTE: WM_CTRLCOLOR is obsolete on Windows NT and Windows 95. Instead, you would use WM_CTLCOLORBTN, WM_CTLCOLORDLG, WM_CTLCOLOREDIT, WM_CTLCOLORLISTBOX, WM_CTLCOLORMSGBOX, WM_CTLCOLORSCROLLBAR, or WM_CTLCOLORSTATIC.

MORE INFORMATION

The following MainWndProc demonstrates WM_CTLCOLOR processing:

long FAR PASCAL MainWndProc(HWND hwnd, unsigned msg,

                            WORD wParam, LONG lParam)
{
static   HWND     hwndEdit;
static   HBRUSH   hBrush;

   switch (msg)
   {
      case WM_CREATE:
         {
            HDC hdc;
            TEXTMETRIC tm;

            hdc = GetDC(hwnd);
            GetTextMetrics(hdc, &tm);
            ReleaseDC(hwnd, hdc);

            hwndEdit = CreateWindow("edit", NULL,
                            WS_CHILD | WS_VISIBLE
                            | ES_AUTOHSCROLL | ES_MULTILINE,
                            10, 20, 100, tm.tmHeight,
                            hwnd, 1, hInst, NULL);

            // Create a blue brush to be used for the edit control's
            // background color.
            hBrush = CreateSolidBrush(RGB(0, 0, 255));
         }
         break;

      case WM_CTLCOLOR:
      {
         // Set foreground and background colors only if this
         // is an edit control.
         if (HIWORD(lParam) == CTLCOLOR_EDIT)
         {
            // Set the edit control's foreground text color to
            // cyan and the text's background color to blue.
            SetTextColor(wParam, RGB(0, 255, 255));
            SetBkColor(wParam, RGB(0, 0, 255));

            // Properly originate the background brush. This is
            // of use if the brush is a pattern instead of a
            // solid color.
            UnrealizeObject(hBrush);
            SetBrushOrg(wParam, 0, 0);

            // Return a handle to the background brush for the edit
            // control.
            return (DWORD)hBrush;
         }
      }
      break;

      case WM_SETFOCUS:
         SetFocus(hwndEdit);
         return 0;

      case WM_DESTROY:
         PostQuitMessage(0);
         DeleteObject(hBrush);
         break;
   }
   return DefWindowProc(hwnd, msg, wParam, lParam);