Q117778: HOWTO: Change the Background Color of an MFC Edit Control
Article: Q117778
Product(s): Microsoft C Compiler
Version(s): 1.0,1.5,1.51,1.52,2.0,2.1,4.0,4.1,4.2,5.0,6.0
Operating System(s):
Keyword(s): kbcode kbMFC KbUIDesign kbVC100 kbVC150 kbVC151 kbVC200 kbVC410 kbVC420 kbVC500 kbVC600
Last Modified: 13-MAY-2002
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The information in this article applies to:
- The Microsoft Foundation Classes (MFC), used with:
- Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5, 1.51, 1.52
- Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 2.1, 4.0, 4.1
- Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 5.0, 6.0
- Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 5.0, 6.0
- Microsoft Visual C++, 32-bit Learning Edition, version 6.0
- Microsoft Visual C++.NET (2002)
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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.
NOTE: In Visual C++ .NET you can add the WM_CTLCOLOR and WM_DESTROY handlers for
the dialog object from the Properties Window. All the available messages for the
dialog are listed in the Messages tab.
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;
}
Additional query words: CEdit
======================================================================
Keywords : kbcode kbMFC KbUIDesign kbVC100 kbVC150 kbVC151 kbVC200 kbVC410 kbVC420 kbVC500 kbVC600 kbGrpDSMFCATL
Technology : kbAudDeveloper kbMFC
Version : :1.0,1.5,1.51,1.52,2.0,2.1,4.0,4.1,4.2,5.0,6.0
Issue type : kbhowto
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