ASP.NET.in.a.Nutshell.Second.Edition [Electronic resources] نسخه متنی

Chapter 42. The System.Web.UI.WebControls Namespace

The System.Web.UI.WebControls
namespace contains types used for
web controls. Web controls are
ASP.NET's most full-featured controls and range from
straightforward elements like Button to
sophisticated controls like Calendar,
AdRotator, and DataGrid. Web
controls are more abstract than HTML controls. Rather than wrapping
specific HTML elements, web controls can consist of a combination of
HTML elements and vary their user interface depending on the
capabilities of the client browser. They also provide a richer set of
formatting properties and events. For example, all input controls
provide an AutoPostback property that, when set to
True, allows your code to react immediately to a
Change event (like a checkbox being checked or a new list selection).

This namespace contains the WebControl class,
which is the base class for all web controls. Web controls include
traditional standards like TextBox,
Button, RadioButton, and
CheckBox, and more unusual and advanced controls
like Calendar, AdRotator, and
the list controls CheckBoxList and
RadioButtonList.

Some of the most interesting controls in this namespace include those
used for data-bound tables. Typically, DataGrid
provides the most powerful options, with features for paging,
sorting, and automatic selection and editing. You can also use the
DataList class for a templated list or the
Repeater class for a simple data-bound repeater
that allows completely customized layout but has no built-in
formatting or support for higher-level features like selection and
editing.

Other useful controls in this namespace include the validation
controls that derive from BaseValidator. These
controls include CompareValidator (which compares
data to an expected value), RangeValidator (which
ensures that data falls in a specified range),
RegularExpressionValidator (which validates data
using a regular expression),
RequiredFieldValidator (which ensures that data
has been entered), and CustomValidator (which
allows you to create your own validation routines). Optionally,
validation results can be displayed using the
ValidationSummary control.

Figure 42-1 shows the
controls in this namespace. Figure 42-2 and Figure 42-3
show the remaining types, including delegates and events.

Figure 42-1. Controls in the System.Web.UI.WebControls namespace

Figure 42-2. Delegates, events, and other types

Figure 42-3. Remaining types from the System.Web.UI.WebControls namespace