We may develop our own server controls by extending an existing control or a group of controls to provide additional functionalities. As stated earlier, there are two versions of custom controls: Web User Controls and Web Custom Controls. The Web User Controls are easy to develop and these are typically stored as ascx files. The Web Custom Controls require in-depth knowledge of Object Oriented Programming and CLR. These are stored in compiled form as assemblies.

A user control, if developed correctly, functions like any other controls. It can be placed inside any other host ASP page (often called the Consumer of a control). In this section we will provide two examples on how to develop and use a Web User Control. In the first example, we will develop a very simple user control. In the second example, we will develop a user control that will expose some of its properties to its host page class.

Creating a Simple Web User Control

Suppose that we want to build the control as shown in Figure 3.88. If a host page embeds this control, it will automatically display the current time in the server s time zone. Once we build this control, we can use it in any subsequent page. We will provide a step-by-step procedure to build this control.

Figure 3.88: A Sample User Control

1. Develop the necessary code for the control. The code for this example is shown in Figure 3.89...