This was my first ActiveX control. I wanted to add the
virtual (or owner-data)
capabilities of the ListView control to the Visual Basic programmer.
The virtual control can handle an outrageous number
of items. Specifically, the control can support an item count
up to 4 billion. This is possible because the overhead of managing item
data is placed on the owner. Whenever the list control needs to display
an item, it will ask the owner (e.g. the Visual Basic Form) about
the displayed data.
The Virtual List control is just as easy to use as the regular List Control in Visual Basic. There are however some differences in the way you set the initial properties and how you manage your data.
How to use it
ItemCount
First of all theItemCount
property is read-write. You
must initialise the control by setting this property to the expected
number of items the control will display.
GetItem event
The control has one important event that you must supply code for: theGetItem
event. This event is fired whenever the
control needs to paint a list item. You are responsible for looking
up the item's text and return it. You can imagine that this
event will fire a lot so careful management (caching) of your
item data is important for performance.
Notes
The download was screwed up. I seem to have lost the updated
source code. Until I find it again, you'll have to stick
with this rather outdated download.
Source Code Dependencies
Microsoft Visual C++ 6.0Microsoft ATL Library
Installation Guide
- Copy the OCX to a directory of your choice and register it using the REGSVR32 utility or use VB to browse for it.
Download Files 
![]() | OCX File (37 Kb) Source Code (64 Kb) |