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The C++Builder IDE Explored: Projects and Forms
Handle
The Handle property returns the window handle (HWND) of the form. Use this property when
you need the window handle to pass to a Windows API function.
ModalResult
The ModalResult property is used to close a modal window. If you have a dialog box that has
OK and Cancel buttons, you can set ModalResult to mrOK when the user clicks the OK button,
and to mrCancel when the user clicks the Cancel button. The calling form can then read
ModalResult to see which button was clicked to close the form. Other possibilities include
mrYes, mrNo, and mrAbort.
Owner
The Owner property is a pointer to the owner of the form. The owner of the form is the object
that is responsible for deleting the form when the form is no longer needed. The parent of
a component, on the other hand, is the window (a form or another component) that acts as
the container for the component. In the case of a main form, the application object is both
the owner of the form and the parent of the form. In the case of components, the owner would
be the form, but the parent could be another component, such as a panel.
Parent
The Parent property is a pointer to the parent of the form. See the previous section about
Owner for an explanation of Owner versus Parent.
Form Methods
Forms are components, too. As such, forms have many methods in common with components.
Common methods include Show(), ShowModal(), and Invalidate(), to name just a
few. There are some methods, however, that are specific to forms. As before, I’ll discuss only
the most commonly used methods.
BringToFront()
The BringToFront() method causes the form to be brought to the top of all other forms in
the application.
Close() and CloseQuery()
The Close() method closes a form after first calling CloseQuery() to be sure that it’s okay to
close the form. The CloseQuery() function, in turn, calls the OnCloseQuery event handler. If
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