windows-7mfccheckboxcbutton

MFC CButton background ignored by Windows 7

To change the appearance (background color and text foreground color) of a MFC checkbox and a radiobutton, I used the following implementation which worked fine in Windows2000, half OK in Windows XP, but not OK in Windows 7:

BEGIN_MESSAGE_MAP(mycheckbox, CButton)
  ...
  ON_WM_CTLCOLOR_REFLECT()
  ...
END_MESSAGE_MAP()

HBRUSH mycheckbox::CtlColor(CDC* pDC, UINT nCtlColor)
{
  pDC->SetBkColor( RGB( 255, 0, 0 ) );
  pDC->SetTextColor( RGB( 0, 255, 0 ) );
  return m_brush;
}

This works fine as long as the Windows Classic theme is used. However, when using a different theme:

I tried OnEraseBkgnd to fill the background with a custom color (pDC->FillSolidRect) but even this had no effect.

I want to avoid using ownerdrawn OnPaint so the check and radio marks keep following the theme that is active in Windows. As written before, this code is used in W2000, Windows Xp, Vista and Windows 7... I just want to change the background color and text color.

Solution

  • I have written a CButton that will use ownerdraw when theming is active in Windows (that is not the case when Windows Classic is used), and will do so dynamically. This sample code is not complete but it demonstrates everything needed to get the results.

    The difficult part is that you need to represent highlighted and pressed states, see the parameters for DrawCheckBox. I am ignoring them as they will not be entirely missed in my application.

    IMPLEMENT_DYNAMIC(mycheckbox, CButton)

mycheckbox::mycheckbox()
  : mv_bIsChecked( false )
{
  m_brush.CreateSolidBrush( RGB( 0,0,255) );
}

mycheckbox::~mycheckbox()
{
}

BEGIN_MESSAGE_MAP(mycheckbox, CButton)
  ON_WM_CTLCOLOR_REFLECT()
  ON_WM_PAINT()
  ON_CONTROL_REFLECT(BN_CLICKED, &mycheckbox::OnBnClicked)
END_MESSAGE_MAP()

HBRUSH mycheckbox::CtlColor(CDC* pDC, UINT nCtlColor)
{
  pDC->SetBkColor( RGB( 255, 0, 0 ) );   // text background color
  pDC->SetTextColor( RGB( 0, 255, 0 ) ); // text foreground color
  return m_brush;                        // control background
}

void mycheckbox::DrawItem(LPDRAWITEMSTRUCT)
{
}

void mycheckbox::OnPaint()
{
  if( ( GetStyle() & BS_OWNERDRAW ) == BS_OWNERDRAW )
  {
    CPaintDC dc( this );

    RECT rect;
    GetClientRect( & rect );
    rect.right = rect.left + 20;
    CMFCVisualManager::GetInstance()->DrawCheckBox(
                & dc
              , rect
              , false                               // highlighted
              , mv_bIsChecked ? 1 : 0 // state
              , true                                // enabled
              , false                               // pressed
              );

    // draw text next to the checkbox if you like
  }
  else
    __super::OnPaint();
}

  // when BS_OWNERDAW is active,
  // GetCheck() is reporting a wrong value
  // so we have to do a little bookkeeping ourselves
void mycheckbox::OnBnClicked()
{
  mv_bIsChecked = ! mv_bIsChecked;
}

BOOL mycheckbox::PreCreateWindow( CREATESTRUCT & cs )
{
  CString lv_szValue;
  CSettingsStore lv_Registry( FALSE, TRUE );
  lv_Registry.Open( _T("Software\\Microsoft\\Windows\\CurrentVersion\\ThemeManager") );
  lv_Registry.Read( _T("ThemeActive"), lv_szValue );
  lv_Registry.Close();
  if( lv_szValue == _T("1") )
    cs.style |= BS_OWNERDRAW;

  return CButton::PreCreateWindow(cs);
}

    I even tried runtime theme switching, however that gives undesired effect when switching from Windows 7 theme to Windows Classic (checkbox then looks like a regular button). So I am not using this but maybe it is interesting to share:

    void mycheckbox::OnNMThemeChanged( NMHDR * pNMHDR, LRESULT * pResult )
{
  CString lv_szValue;
  CSettingsStore lv_Registry( FALSE, TRUE );
  lv_Registry.Open( _T("Software\\Microsoft\\Windows\\CurrentVersion\\ThemeManager") );
  lv_Registry.Read( _T("ThemeActive"), lv_szValue );
  lv_Registry.Close();

  ModifyStyle( BS_OWNERDRAW, 0 ); // turn off
  if( lv_szValue == _T("1") )
    ModifyStyle( 0, BS_OWNERDRAW ); // turn on

  // This feature requires Windows XP or greater.
  // The symbol _WIN32_WINNT must be >= 0x0501.
  // TODO: Add your control notification handler code here
  *pResult = 0;
}