Using ON_UPDATE_COMMAND_UI with controls

afxpriv.h has a message, WM_KICKIDLE, that is sent during idle processing. To get dialogs to work with the ON_UPDATE_COMMAND_UI message maps, you need to trap the kick idle message and call UpdateDialogControls.

In a dalog class header, add the following in the message map:

	afx_msg LRESULT OnKickIdle(WPARAM , LPARAM );

In the implementation file:

	#include <afxpriv.h>

In the message map add:

	ON_MESSAGE(WM_KICKIDLE, OnKickIdle)

Implement the function:

	LRESULT CMyDlg::OnKickIdle(WPARAM wParam, LPARAM lParam)
	{
		UpdateDialogControls(this, FALSE);
		return 0;
	}

I leave the bDisableIfNoHndler flag as FALSE so buttons without message map entries are not disabled.

You can now use ON_UPDATE_COMMAND_UI message maps for enabling/disabling controls, setting static text, etc.

It works really well when you have two or more radio buttons that enable/disable different groups of controls. Just have one OnUpdate... function for each group of controls that enables/disables depending on the radio button selected, use IsDlgButtonChecked. Then add a message map entry for each control.

To use ON_UPDATE_COMMAND_UI in form views.

The kick idle message doesn't work in form views, but there's another message in afxpriv.h called WM_IDLEUPDATECMDUI, that does.

In a form view class header, add the following in the message map:

	afx_msg LRESULT OnIdleUpdateCmdUI(WPARAM , LPARAM );

In the implementation file:

	#include <afxpriv.h>

In the message map add:

	ON_MESSAGE(WM_IDLEUPDATECMDUI, OnIdleUpdateCmdUI)

Implement the function:

	LRESULT CMyFormView::OnIdleUpdateCmdUI(WPARAM wParam, LPARAM)
	{
		UpdateDialogControls(this, FALSE);
		return 0L;
	}

ON_UPDATE_COMMAND_UI can now be used as described above.

Updated 21 March 1998