Teach Yourself Borland C++ in 14 Days - portal

296 Day 8
NOTE
As with the edit components we looked at earlier, there are very few ListBox and ComboBox
methods. The Clear() method will clear the control of all data. The ItemAtPos() methods
will return the list box item at the specified x and y coordinates. The SelectAll() method
will select the text in the edit control portion of a combo box.
Easily the most-used event when dealing with combo boxes and list boxes is the OnClick
event. Use this event to determine when a selection has been made in the list box.
Clicking on the edit portion of a combo box or the drop-down button
does not result in an OnClick event being sent. Only when the list box
portion of a combo box is clicked will the OnClick event occur.
The OnChange event can be used to detect changes to the edit portion of a combo box just as
it is used with edit controls. The OnDropDown event is used to detect when the drop-down
button on a combo box has been clicked. The OnMeasureItem and OnDrawItem events are used
with owner-drawn list boxes and owner-drawn combo boxes.
Button, Button, Who’s Got the Button?
NOTE
VCL contains several types of buttons that you can use in your applications. Although not
all of them could be considered to be based on the standard Windows button control, I will
still address all the button types here. Before we look at the specific button components,
though, let’s cover some of the basics.
When setting the Caption property of a button, use the ampersand (&)
just as you would when setting the Caption property of menu items.
The character after the ampersand will be underlined and will be the
accelerator for the button.
Button Basics
The button components only have about three properties of note.
The ModalResult Property
The ModalResult property is used to provide built-in form closing for forms displayed with
ShowModal(). By default, ModalResult is set to mrNone (which is #defined as 0). Use this value