HOWTO: Change the Background Color of an MFC Edit Control

• The Microsoft Foundation Classes (MFC) included with:

      - Microsoft Visual C++ for Windows, versions 1.0, 1.5, 1.51, 1.52
      - Microsoft Visual C++ 32-bit Edition, versions 1.0, 2.0, 2.1, 4.0,
        4.1, 4.2, 5.0
  

SUMMARY

To change the background color of an edit control in an MFC application, you must override the OnCtlColor() message-handling function of the window containing the edit control.

In the new OnCtlColor() function, set the background color and return a handle to a brush that will be used for painting the background. This must be done in response to receiving both the CTLCOLOR_EDIT and CTLCOLOR_MSGBOX messages in the OnCtlColor() function.

This is also documented in the "Class Library Reference" under CWnd::OnCtlColor().

MORE INFORMATION

The sample code below uses a CDialog-derived class to demonstrate the process. Class Wizard was used to generate message-handling functions for the WM_CTLCOLOR and WM_DESTROY messages. These functions are called CEditDialog::OnCtlColor() and CEditDialog::OnDestroy(), respectively.

Sample Code

      // editdlg.h : header file
      //

////////////////////////////////////////////////////////////////////////
      ///
      // CEditDialog dialog

      class CEditDialog : public CDialog
      {
      // Construction
      public:
          CEditDialog(CWnd* pParent = NULL);    // standard constructor

      // Add a CBrush* to store the new background brush for edit controls.
          CBrush* m_pEditBkBrush;

      // Dialog Data
          //{{AFX_DATA(CEditDialog)
          enum { IDD = IDD_EDITDIALOG };
              // NOTE: The ClassWizard will add data members here.
          //}}AFX_DATA

      // Overrides
      // ClassWizard generated virtual function overrides
      //{{AFX_VIRTUAL(CEditDialog)
      protected:
      virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
      //}}AFX_VIRTUAL

      // Implementation
         protected:

          // Generated message map functions
          //{{AFX_MSG(CEditDialog)
          afx_msg HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor);
          afx_msg void OnDestroy();
          //}}AFX_MSG
          DECLARE_MESSAGE_MAP()
      };

      // editdlg.cpp : implementation file
      //

      #include "stdafx.h"
      #include "mdi.h"
      #include "editdlg.h"

      #ifdef _DEBUG
      #undef THIS_FILE
      static char BASED_CODE THIS_FILE[] = __FILE__;
      #endif

   //////////////////////////////////////////////////////////////////////
      // CEditDialog dialog

      CEditDialog::CEditDialog(CWnd* pParent /*=NULL*/)
          : CDialog(CEditDialog::IDD, pParent)
      {
          //{{AFX_DATA_INIT(CEditDialog)
              // NOTE: The ClassWizard will add member initialization here.
          //}}AFX_DATA_INIT

          // Instantiate and initialize the background brush to black.
          m_pEditBkBrush = new CBrush(RGB(0, 0, 0));
      }

      void CEditDialog::DoDataExchange(CDataExchange* pDX)
      {
          CDialog::DoDataExchange(pDX);
          //{{AFX_DATA_MAP(CEditDialog)
              // NOTE: The ClassWizard will add DDX and DDV calls here.
          //}}AFX_DATA_MAP
      }

      BEGIN_MESSAGE_MAP(CEditDialog, CDialog)
          //{{AFX_MSG_MAP(CEditDialog)
          ON_WM_CTLCOLOR()
          ON_WM_DESTROY()
          //}}AFX_MSG_MAP
      END_MESSAGE_MAP()

//////////////////////////////////////////////////////////////////////
      // CEditDialog message handlers

      HBRUSH CEditDialog::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
      {
          switch (nCtlColor) {

          case CTLCOLOR_EDIT:
          case CTLCOLOR_MSGBOX:
              // Set color to green on black and return the background
                 brush.
              pDC->SetTextColor(RGB(0, 255, 0));
              pDC->SetBkColor(RGB(0, 0, 0));
              return (HBRUSH)(m_pEditBkBrush->GetSafeHandle());

          default:
              return CDialog::OnCtlColor(pDC, pWnd, nCtlColor);
          }
      }

      void CEditDialog::OnDestroy()
      {
          CDialog::OnDestroy();

          // Free the space allocated for the background brush
          delete m_pEditBkBrush;
      }