Setting selected text to read-only

Step 1: Set the ENM_PROTECTED event mask

void CMyRichEditView::OnInitialUpdate()
{
	CRichEditView::OnInitialUpdate();

	long eventmask = GetRichEditCtrl().GetEventMask() | ENM_PROTECTED;
	GetRichEditCtrl().SetEventMask( eventmask );
}

If instead, you are deriving from CRichEditCtrl, you can set the event mask in the PreSubclassWindow() function after calling the base class version of the function.

Step 2: Add handler for EN_PROTECTED

The class wizard does not help in adding a handler for the EN_PROTECTED notification; you will have to add it manually. First the code snippet from the header file.

	//{{AFX_MSG(CMyRichEditView)
	:
	:
	//}}AFX_MSG
	afx_msg void OnProtected(NMHDR* pNMHDR, LRESULT* pResult);
	DECLARE_MESSAGE_MAP()

Now the message map entry in the implementation file and the function definition. In the handler we simply set the result to TRUE. This will disallow any change. If you want to allow editing in special circumstances, this is where you would add to code to decide whether to allow the edit.

BEGIN_MESSAGE_MAP(CMyRichEditView, CRichEditView)
	//{{AFX_MSG_MAP(CMyRichEditView)
	:
	:
	//}}AFX_MSG_MAP
	ON_NOTIFY_REFLECT(EN_PROTECTED, OnProtected)
END_MESSAGE_MAP()


void CMyRichEditView::OnProtected(NMHDR* pNMHDR, LRESULT* pResult) 
{
	ENPROTECTED* pENPROTECTED = (ENPROTECTED* )pNMHDR;


	// Returning non zero will disallow change
	*pResult = TRUE;
}

Step 3: Change the character format to protected

void CMyRichEditView::SetSelectionProtected() 
{
	CHARFORMAT cf;

	cf.cbSize = sizeof( cf );
	cf.dwMask = CFM_PROTECTED;
	cf.dwEffects = CFE_PROTECTED;

	GetRichEditCtrl().SetSelectionCharFormat( cf );
}