Advanced MFC Programming

Chapter 2. Menu
“clipboard”. We can indicate the data status by putting a check mark on the menu item so the user knows if
the current “data” in the “clipboard” has been pasted (after the user executes View | Paste command). This
check will be removed when either “cut” or “copy” command is executed.
Similar to tool bar, we can call function CCmdUI::SetCheck(…) to set check for a menu item. The
difference between the results of this function is the changing on the interface: while setting check for a
button will make it recess, setting check for a menu item will put a check mark at the left side of the menu
item.
We need a new Boolean type variable to indicate the status of “data”. In the sample application, this
variable is CMenuDoc::m_bDataPasted, which is initialized to FALSE in the constructor. The following
functions show how its value is changed under different situations:
void CMenuDoc::OnEditCopy()
{
m_bPasteAvailable=TRUE;
m_bDataPasted=FALSE;
}
void CMenuDoc::OnEditCut()
{
m_bPasteAvailable=TRUE;
m_bDataPasted=FALSE;
}
void CMenuDoc::OnEditPaste()
{
m_bDataPasted=TRUE;
}
In function OnUpdateEditPaste(…), the menu item is checked only when flag CMenuDoc::
m_bDataPasted is TRUE:
void CMenuDoc::OnUpdateEditPaste(CCmdUI* pCmdUI)
{
pCmdUI->Enable(m_bPasteAvailable);
pCmdUI->SetCheck(m_bDataPasted);
pCmdUI->SetText
(
m_bPasteAvailable ?
(m_bDataPasted ? "Data &pasted":"Please &paste"):
"Do not &paste"
);
}
The text of the menu item is also change to “Data pasted” when the menu item is checked.
The last thing need to be mentioned here is another member function of class CCmdUI: CCmdUI::
SetRadio(…). Like CCmdUI::SetCheck(…), this function will put a check mark on a menu item. The
difference between two functions is that CCmdUI::SetRadio(…) makes menu items behave like radio
buttons: when this function is called to check one item, all other items in the same group will be unchecked
automatically. Calling function CCmdUI::SetCheck(…) does not affect other menu items.
2.2 Right Click Pop Up Menu
In Windows 95, right-click menu becomes a standard user interface. We can right click on the
desktop, task bar, or other types of windows to bring up a menu that contains the most commonly used
commands. In this section, we will discuss how to add right-click menu to our application.
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