Jump to content
  • Advertisement
Sign in to follow this  
crazy_andy

disableing menu items - mfc

This topic is 4965 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I have an MFC program with: CMenu menu1; menu1.LoadMenu(IDR_MENU1); SetMenu(&menu1); now this loads a menu perfectly fine. When I cleck file new (ID_FILE_NEW) I want to disable it, so it cant be pressed again. Im trying: menu1.EnableMenuItem(ID_FILE_NEW,MF_BYCOMAND|MF_GRAYED); now this returns -1 suggesting the menu item doesn't exist, but when I click on the new button in the resource editor, it says ID ID_FILE_NEW so what am I doing wrong? I have been googleing for ages but no success

Share this post


Link to post
Share on other sites
Advertisement
Try this:

CMenu* mmenu = GetMenu();
CMenu* submenu = mmenu->GetSubMenu(0);
submenu->EnableMenuItem(ID_FILE_NEW, MF_BYCOMMAND | MF_DISABLED | MF_GRAYED);

Share this post


Link to post
Share on other sites
nope, it just displayed the menu as normal.

here is my code:


class MFC_Tutorial_Window :public CFrameWnd
{
CMenu menu1; // dedines my menu
public:
HANDLE tThread;
MFC_Tutorial_Window()
{
Create(NULL,"Countdown - ALPHA V 0.2"); // creates window

menu1.LoadMenu(IDR_MENU1); // sets up menu
SetMenu(&menu1);
// UINT t = menu1.EnableMenuItem // here I want to grey out the new button.(ID_FILE_NEW,MF_BYCOMMAND|MF_GRAYED);
}


void OnClickNew(); // defines function for when the new button is clicked
void OnClickStatusT1();
void OnClickExitApp();
void OnClickAbout();
int OnCreate(LPCREATESTRUCT lpCreateStruct);
void OnClose();
DECLARE_MESSAGE_MAP() // sets up a message map, for message handling
};

Share this post


Link to post
Share on other sites
OK, ive still not had any luck, It just doesn't grey out. should I try creating the menu at runtime rather than as a resource?

Share this post


Link to post
Share on other sites
I haven't touched MFC in ages, but I think this is the cause. Before displaying a menu MFC updates each menu item automatically. If it's missing an ON_COMMAND entry in a message map somewhere the menu item is automatically disabled, otherwise it's automatically enabled. CWinApp might have an update handler for ID_FILE_NEW by default, which is what is enabling the menu again.

This page describes a way to disable this. In your constructor for MFC_Tutorial_Window try adding this:

MFC_Tutorial_Window()
{
m_bAutoMenuEnable = false;
}
Ideally you'd have a message map entry to handle ID_FILE_NEW, and then you could simply add ON_UPDATE_COMMAND_UI(ID_FILE_NEW, OnUpdateFileNew) and call pCmdUI->Enable(false) from OnUpdateFileNew(CCmdUI* pCmdUI). How does your message map look like?

Update: Fixed incorrect information.

Share this post


Link to post
Share on other sites
ok, I tried that but I'm getting an unresolved external. heres my message map


class MFC_Tutorial_Window :public CFrameWnd
{
CMenu menu1; // dedines my menu
public:
HANDLE tThread;
MFC_Tutorial_Window()
{
m_bAutoMenuEnable = false;
Create(NULL,"Countdown - ALPHA V 0.2"); // creates window

menu1.LoadMenu(IDR_MENU1); // sets up menu
SetMenu(&menu1);
// UINT t = menu1.EnableMenuItem(ID_FILE_NEW,MF_BYCOMMAND|MF_GRAYED);
}


void OnClickNew(); // defines function for when the new button is clicked
void OnClickStatusT1();
void OnClickExitApp();
void OnClickAbout();
int OnCreate(LPCREATESTRUCT lpCreateStruct);
void OnClose();
void OnUpdateFileNew(CCmdUI* pCmdUI);
DECLARE_MESSAGE_MAP() // sets up a message map, for message handling
};

BEGIN_MESSAGE_MAP( MFC_Tutorial_Window, CFrameWnd) // begining of message map
ON_WM_CREATE()
ON_WM_CLOSE()
ON_COMMAND(ID_FILE_NEW,OnClickNew) // when new is clicked do function OnClickNew()
ON_COMMAND(ID_HELP_ABOUT,OnClickAbout)
ON_COMMAND(ID_STATUS_TIMER1,OnClickStatusT1)
ON_COMMAND(IDEXIT,OnClickExitApp)
ON_UPDATE_COMMAND_UI(ID_FILE_NEW,OnUpdateFileNew) // unresolved external here
END_MESSAGE_MAP() // end of message map

void OnUpdateFileNew(CCmdUI* pCmdUI)
{
pCmdUI->Enable(false);
}

void MFC_Tutorial_Window::OnClickNew() // what to do when new is clicked
{
newDialog dlg; //defines dialog box
dlg.DoModal();
}
...

Share this post


Link to post
Share on other sites
Oh, I probably should've worded things clearer.

Solution 1: Add the m_bAutoMenuEnable line. I don't know if this works.

Solution 2: Add ON_UPDATE_COMMAND_UI, this is probably the preferred solution since it integrates into MFC's message map, command updating framework. Ahh I wrote out a bunch of stuff describing how to implement it. Turns out you're just missing one thing.


void OnUpdateFileNew(CCmdUI* pCmdUI)

// should be

void MFC_Tutorial_Window::OnUpdateFileNew(CCmdUI* pCmdUI)




Of course now you won't be able to click the ID_FILE_NEW menuitem since it'll always be disabled. If you want to disable it after one click, try this:


class MFC_Tutorial_Window : public CFrameWnd
{
bool m_bEnableFileNew;

MFC_Tutorial_Window()
{
m_bEnableFileNew = true;

// ...
}

// ...
}

void OnUpdateFileNew(CCmdUI* pCmdUI)
{
// the nice thing about this is that it'll also disable toolbar buttons that
// have an ID of ID_FILE_NEW
pCmdUI->Enable(m_bEnableFileNew);
}

void MFC_Tutorial_Window::OnClickNew()
{
// disable file new. next time the menu displays MFC will call OnUpdateFileNew,
// which will disable the menu item.
m_bEnableFileNew = false;

newDialog dlg;
dlg.DoModal();
}

// ...



Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!