ASP.NET 4 Unleashed

Using the UpdatePanel Control

Microsoft’s server-side AJAX framework consists of one main control: UpdatePanel. The UpdatePanel control enables you to update a portion of a page without updating the entire page. In other words, it enables you to perform partial-page rendering.

Let’s start with a super-simple example of a page that uses the UpdatePanel control. The page in Listing 38.1 contains a ScriptManager control and an UpdatePanel control. The UpdatePanel control contains a single Button control. When you click the button, only the content contained in the UpdatePanel control is refreshed (see Figure 38.3).

Figure 38.3. Using the UpdatePanel control.

Listing 38.1. UpdatePanelSimple.aspx

The page in Listing 38.1 displays the current ...