ASP.NET contains a large set of useful controls that each
developer may require while developing web or windows applications. However, we
as developers do not find all of the controls that we think of simply
out-of-the-box. At the same time, since the .NET Framework is based on the
object oriented concepts and since we have the server-side controls as objects,
building new controls out of the existing controls is pretty simple and easy!
There are different kinds of custom control development,
ranging from rendered controls to inherited controls, and finally the composite
In this article we are going to develop a composite control
that will make use of two xListBox, which is the control that we have developed
few weeks ago and published on ASPAlliance.com where we fixed the issue of
maintaining any changes in the ListBox items on the client side on the server.
If you have not yet read that article, it is advisable to check it first before
going on this article.
In addition to the two listboxes that we will use, two
buttons are placed just in between the two listboxes. Those two controls will
be used by end users to move items from one listbox to another and vice versa.
Continue reading down the sections to follow the steps
required to build such a control in an organized and well explained way.