By default, every control on a Visual Basic 6 form is an
independent entity with its own name and its own event procedures. In some
situations, you can simplify your programming work by using a control array.
This permits two or more controls of the same type to have the same name and
same event procedures but retain their own separate properties. This tip shows
To create a control array, you must put a single control of
the desired type on the form. With the control selected, press [Ctrl]C and then [Ctrl]V. Visual Basic will display the following
You already have a control named XXXXX. Do you want to create a control array?
Click Yes. Now you’ll have two identical controls–Command
Buttons, Check Boxes, or whatever–on the form. Repeat the steps to add more
controls to the array. (There is no limit to the size of a control array other
than those imposed by system resources, although you’ll rarely find arrays of
more than 8-12 controls to be useful.)
When you select a control in an array, the Properties window
displays its properties. Except for the Name, these properties are completely
independent from other controls in the array. If all the controls have the same
name, how can you tell them apart? The answer lies in the Index property. The first control in an array has Index = 0, the
second control has Index = 1, and so on. Controls that aren’t part of an array
have a blank Index property.
As I mentioned, all the controls in an array share the same
event procedures. The procedure is passed an argument indicating the Index
property of the control that received the event. This is where the usefulness
of control arrays is most evident. You can write a single event procedure that
handles the events for multiple controls. For example, you could create an
array of three Command Button controls and then write the Click event procedure
Private Sub Command1_Click(Index As Integer)
Select Case Index
‘ Code for first action here.
‘ Code for second action here.
‘ Code for third action here.
Keeping code together like this rather than spreading it out
over multiple event procedures makes it easier to write and debug.
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