EnableMenuItem problem

Hello,
I have an MDI application and having problems disabling or graying an item in the drop-down menu. I am using visual studio 2015

The drop-down menu is fourth from the left. Zero-based 3. The code is:

Code:

---

CWnd* pMain = AfxGetMainWnd();

if (pMain != NULL)
{
  CMenu* pMenu = pMain->GetMenu()->GetSubMenu(3); 

  // following test count agrees with number of drop-down menu items
  int count = pMenu->GetMenuItemCount();       

  if (pMenu != NULL && pMenu->GetMenuItemCount() > 0)
 {
    BOOL res = pMenu->EnableMenuItem(ID_ANALYZE, MF_BYCOMMAND | MF_GRAYED);

    pMain->DrawMenuBar();
 }

---

BOOL res returns 0 which indicates to me that the EnableMenuItem command was successful.

But the menu item is not GRAYED!

I've tried different methods including by position, but nothing works! For example,

Code:

---

BOOL res = pMenu->EnableMenuItem(ID_MENUID, MF_BYCOMMAND | MF_GRAYED |MF_DISABLED);

BOOL res = pMenu->EnableMenuItem(3, MF_POSITION | MF_DISABLED);

---

Any suggestions?

Thank you in advance

Try to enable/disable those menu item trough message map, just like this:

Code:

---

BEGIN_MESSAGE_MAP(CYourView, CListView)
        ON_UPDATE_COMMAND_UI(ID_MENUID, OnUpdateItem)
END_MESSAGE_MAP()

---

I have been trying to do this

Code:

---

BEGIN_MESSAGE_MAP(….)
ON_UPDATE_COMMAND_UI(ID_MENUID, OnUpdateShowResults)

void CAppDoc::OnUpdateShowResults(CCmdUI* pCmdUI)
{
        pCmdUI->Enable(FALSE);
}

---

But I can’t find the correct code way to issue the OnUpdateShowResults() command inside the code.

But the following generates an exception.
Exception thrown: read access violation.
pCmdUI was nullptr

OnUpdateShowResults(FALSE);

Are you calling the handler OnUpdateShowResults(FALSE); directly? If so, you shouldn't be calling this directly because the framework will call this for you since you have added an ON_COMMAND_UPDATE_UI map entry. Put a breakpoint inside the handler to make sure it is getting called.

[When posting code, please use code tags. Go Advanced, select the formatted code and click '#'].

Cheers!

Quote:

---

Originally Posted by Arjay

Are you calling the handler OnUpdateShowResults(FALSE); directly? If so, you shouldn't be calling this directly because the framework will call this for you since you have added an ON_COMMAND_UPDATE_UI map entry. Put a breakpoint inside the handler to make sure it is getting called.

---

The whole point is for the program to be able to disable/enable a drop-down menu item directly without user intervention.

For which reason I was trying unsuccessfully to do this thru the CMenu class. Please see my opening post to this thread.

Per suggestion by mesajflaviu, I began trying to accomplish this thru the message map and by calling the handler directly.

I had placed a breakpoint at the handler and the read access violation occurs at:

Code:

---

pCmdUI->Enable(FALSE);

---

thank you...

See Arjay's post. Don't call the handler directly. The framework will call it when it needs to.

The only way to call the handler INDIRECTLY is for the user to click on the menu item.

But as I have been trying to explain, that is what I am trying to prevent to begin with by disabling it programatically.

I am back to square one. There may be a way to get the CMenu - EnableMenuItem to work.

Quote:

---

Originally Posted by robertzp

The only way to call the handler INDIRECTLY is for the user to click on the menu item.

But as I have been trying to explain, that is what I am trying to prevent to begin with by disabling it programatically.

I am back to square one. There may be a way to get the CMenu - EnableMenuItem to work.

---

You are coding it wrong; otherwise, your update ui handler would get called as the menu item is getting displayed and the menu item would be disabled.

Oh, and I get that you think no one UNDERSTANDS your problem even if a few of us answering have programmed in MFC for 20+ years.

If you want to enable / disable that menu item programmatically then you only made a condition inside your UpdateMenu handler ... something like this:

Code:

---

void CAppDoc::OnUpdateShowResults(CCmdUI* pCmdUI)
{
        pCmdUI->Enable(m_bCond);
}

---

and somewhere in your app:

Code:

---

m_bCond = TRUE // or FALSE;

---

and framwork will do the job :)

Quote:

---

Originally Posted by mesajflaviu

If you want to enable / disable that menu item programmatically then you only made a condition inside your UpdateMenu handler ... something like this:

Code:

---

void CAppDoc::OnUpdateShowResults(CCmdUI* pCmdUI)
{
        pCmdUI->Enable(m_bCond);
}

---

and somewhere in your app:

Code:

---

m_bCond = TRUE // or FALSE;

---

and framework will do the job :)

---

My apologies to all.

I made a mistake in coding the message handler. The menu items are now being enabled / disabled programatically.

thanks for your time.

Zip up a small project that shows the reproductive and post it here.