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Recipe 8.3 Make Combo Boxes Load Faster
8.3.1 Problem
Sometimes you need to use combo boxes that
list many items. It takes the user a long time to scroll to the
bottom of the list, because the list loads only a few rows at a time.
Is there any way to get the list to load all at once?
8.3.2 Solution
There is a very simple VBA technique that forces the rows of a combo
or list box to load all at once when you open the form. All you have
to do is force the code behind the form to calculate the number of
items in the list.Load frmComboFast in 08-03.MDB . Click the down
arrow of the top combo box and scroll to the bottom of the list.
Access loads only part of the list each time you scroll, so it takes
many attempts to get to the last items on the list. Now do the same
with the second combo box. This time, you can scroll immediately to
the last item on the list.
8.3.3 Discussion
The Load event procedure in
frmComboFast forces the second combo box to load the entire list, by
calling the ListCount property of the control:
Private Sub Form_Load( )
Dim lngCount As Long
lngCount = cboFast.ListCount
End Sub
To use this code on your form, simply change the name of the control
from cboFast to the name of your combo or list box. You can handle
multiple controls by reusing the lngCount
variable to retrieve the ListCount property value for each combo or
list box that you want to load.The form in this example loads a bit slower than it would if you
didn't use this technique, because load time is
sacrificed in order to improve the performance of the second combo
box. If you need to use combo boxes that have very long lists, this
is a price that your users probably will be quite willing to pay.
