the familiar elements of a graphical user interface (GUI):
buttons, drop-down boxes, checkboxes, etc. Server controls are
controls that enable server-side processing. They provide a range of
functionality, from simple data entry to complex data validation.
ASP.NET ships with a suite of ready-to-run server controls you can
use to develop powerful Web Forms pages. A key component of the
ASP.NET development model, these server controls abstract significant
amounts of programming logic into simple-to-use tags. Server controls
make it easy to separate programmatic logic from UI elements using
code-behind, because you typically instantiate the controls using a
tag-based syntax while keeping your UI-related logic in a separate
code-behind file. In practical terms, this means that programmers can
hand over a .aspx page to UI designers without
having to worry about their programming logic getting completely
ruined in the process.
In ASP.NET, it's easy for developers to create their
own controls from scratch or to build on the functionality of
existing controls by creating user controls that combine HTML, server
controls, and other page elements, or by creating their own custom
server controls. We'll discuss both techniques in
ASP.NET Server Controls are classified as either
web controls. This
chapter summarizes the standard controls and the various methods for
creating and modifying them.