How to restrict some items to be not selected in CComboBox?

[sgrm123]

In a MFC dialog box I am using CComboBox with CBS_DROPDOWNLIST. It is an ownerdraw CComboBox.

I am listing Group name and items of group in the listbox. using the sourcecode given in the link https://www.codeproject.com/Articles/450/CComboBox-with-disabled-items

When I select or click group name, the edit control of CComboBox should not be updated group item text. In that link they are following things to get rid of selection group item.

• 
  Overriding the WM_LBUTTONUP handler of the enclosed list box, we can actually disable clicking on the group items.
  
• 
  Overriding CharToItem handler, we can disable picking the group items by keyboard.
  
• 
  Andfinally, by reacting to reflected CBN_SELENDOK, we can assure that a group item was not selected.
  

const UINT nMessage=::RegisterWindowMessage("ComboSelEndOK");


BEGIN_MESSAGE_MAP(CODrawCombo, CComboBox)
ON_CONTROL_REFLECT(CBN_SELENDOK, OnSelendok)
ON_REGISTERED_MESSAGE(nMessage, OnRealSelEndOK)
ON_CONTROL_REFLECT(CBN_EDITUPDATE, OnComboEdited)
ON_MESSAGE(WM_CTLCOLORLISTBOX, OnCtlColor)
END_MESSAGE_MAP()

void CODrawCombo::OnSelendok()
{
// TODO: Add your control notification handler code here
GetWindowText(m_strSavedText);
PostMessage(nMessage);
}

LRESULT CODrawCombo::OnRealSelEndOK(WPARAM,LPARAM)
{
CString currentText;
GetWindowText(currentText);

int index=FindStringExact(-1,currentText);
if (index>=0 && !IsItemEnabled)
{
SetWindowText(m_strSavedText);
GetParent()->SendMessage(WM_COMMAND,MAKELONG(GetWindowLong(m_hWnd,GWL_ID),CBN_SELCHANGE),(LPARAM)m_hWnd);
}
return 0;
}


void CListBoxInsideComboBox::OnLButtonUp(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
CRect rect; GetClientRect(rect);

if (rect.PtInRect(point))
{
BOOL outside=FALSE;
int index=((CListBox *)this)->ItemFromPoint(point,outside);
if (!outside && !m_Parent->IsItemEnabled(index))
return; // don't click there
}

CWnd::OnLButtonUp(nFlags, point);
}



After clicking group item and if I click outside of CListBox, the edit control of CComboBox updated with group name only? how to resolve this?



In a MFC dialog box I am using CComboBox with CBS_DROPDOWNLIST. It is an ownerdraw CComboBox.

I am listing Group name and items of group in the listbox. using the sourcecode given in the link https://www.codeproject.com/Articles/450/CComboBox-with-disabled-items

When I select or click group name, the edit control of CComboBox should not be updated group item text. In that link they are following things to get rid of selection group item.

• 
  Overriding the WM_LBUTTONUP handler of the enclosed list box, we can actually disable clicking on the group items.
  
• 
  Overriding CharToItem handler, we can disable picking the group items by keyboard.
  
• 
  Andfinally, by reacting to reflected CBN_SELENDOK, we can assure that a group item was not selected.
  
  const UINT nMessage=::RegisterWindowMessage("ComboSelEndOK");
  
  
  BEGIN_MESSAGE_MAP(CODrawCombo, CComboBox)
  ON_CONTROL_REFLECT(CBN_SELENDOK, OnSelendok)
  ON_REGISTERED_MESSAGE(nMessage, OnRealSelEndOK)
  ON_CONTROL_REFLECT(CBN_EDITUPDATE, OnComboEdited)
  ON_MESSAGE(WM_CTLCOLORLISTBOX, OnCtlColor)
  END_MESSAGE_MAP()
  
  void CODrawCombo::OnSelendok()
  {
  // TODO: Add your control notification handler code here
  GetWindowText(m_strSavedText);
  PostMessage(nMessage);
  }
  
  LRESULT CODrawCombo::OnRealSelEndOK(WPARAM,LPARAM)
  {
  CString currentText;
  GetWindowText(currentText);
  
  int index=FindStringExact(-1,currentText);
  if (index>=0 && !IsItemEnabled)
  {
  SetWindowText(m_strSavedText);
  GetParent()->SendMessage(WM_COMMAND,MAKELONG(GetWindowLong(m_hWnd,GWL_ID),CBN_SELCHANGE),(LPARAM)m_hWnd);
  }
  return 0;
  }
  
  
  void CListBoxInsideComboBox::OnLButtonUp(UINT nFlags, CPoint point)
  {
  // TODO: Add your message handler code here and/or call default
  CRect rect; GetClientRect(rect);
  
  if (rect.PtInRect(point))
  {
  BOOL outside=FALSE;
  int index=((CListBox *)this)->ItemFromPoint(point,outside);
  if (!outside && !m_Parent->IsItemEnabled(index))
  return; // don't click there
  }
  
  CWnd::OnLButtonUp(nFlags, point);
  }
  

After clicking group item and if I click outside of CListBox, the edit control of CComboBox updated with group name only? how to resolve this?


In a MFC dialog box I am using CComboBox with CBS_DROPDOWNLIST. It is an ownerdraw CComboBox.

I am listing Group name and items of group in the listbox. using the sourcecode given in the link https://www.codeproject.com/Articles/450/CComboBox-with-disabled-items

When I select or click group name, the edit control of CComboBox should not be updated group item text. In that link they are following things to get rid of selection group item.

• 
  Overriding the WM_LBUTTONUP handler of the enclosed list box, we can actually disable clicking on the group items.
  
• 
  Overriding CharToItem handler, we can disable picking the group items by keyboard.
  
• 
  Andfinally, by reacting to reflected CBN_SELENDOK, we can assure that a group item was not selected.
  
  const UINT nMessage=::RegisterWindowMessage("ComboSelEndOK");
  
  
  BEGIN_MESSAGE_MAP(CODrawCombo, CComboBox)
  ON_CONTROL_REFLECT(CBN_SELENDOK, OnSelendok)
  ON_REGISTERED_MESSAGE(nMessage, OnRealSelEndOK)
  ON_CONTROL_REFLECT(CBN_EDITUPDATE, OnComboEdited)
  ON_MESSAGE(WM_CTLCOLORLISTBOX, OnCtlColor)
  END_MESSAGE_MAP()
  
  void CODrawCombo::OnSelendok()
  {
  // TODO: Add your control notification handler code here
  GetWindowText(m_strSavedText);
  PostMessage(nMessage);
  }
  
  LRESULT CODrawCombo::OnRealSelEndOK(WPARAM,LPARAM)
  {
  CString currentText;
  GetWindowText(currentText);
  
  int index=FindStringExact(-1,currentText);
  if (index>=0 && !IsItemEnabled)
  {
  SetWindowText(m_strSavedText);
  GetParent()->SendMessage(WM_COMMAND,MAKELONG(GetWindowLong(m_hWnd,GWL_ID),CBN_SELCHANGE),(LPARAM)m_hWnd);
  }
  return 0;
  }
  
  
  void CListBoxInsideComboBox::OnLButtonUp(UINT nFlags, CPoint point)
  {
  // TODO: Add your message handler code here and/or call default
  CRect rect; GetClientRect(rect);
  
  if (rect.PtInRect(point))
  {
  BOOL outside=FALSE;
  int index=((CListBox *)this)->ItemFromPoint(point,outside);
  if (!outside && !m_Parent->IsItemEnabled(index))
  return; // don't click there
  }
  
  CWnd::OnLButtonUp(nFlags, point);
  }
  

After clicking group item and if I click outside of CListBox, the edit control of CComboBox updated with group name only? how to resolve this?

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