UpdatePanel Control Overview

Introduction

ASP.NET UpdatePanel controls enable you to build rich, client-centric Web applications. By using UpdatePanel controls, you can refresh selected parts of the page instead of refreshing the whole page with a postback. This is referred to as performing a partial-page update. A Web page that contains a ScriptManager control and one or more UpdatePanelcontrols can automatically participate in partial-page updates, without custom client script.

This topic contains information about the following:

Scenarios

The UpdatePanel control is a server control that helps you develop Web pages with complex client behavior that makes a Web page appear more interactive to the end user. Coordinating between server and client to update only specified parts of a Web page usually requires in-depth knowledge of ECMAScript (JavaScript). However, by using theUpdatePanel control, you can enable a Web page to participate in partial-page updates without writing any client script. If you want, you can add custom client script to enhance the client user experience. When you use an UpdatePanelcontrol, the page behavior is browser independent and can potentially reduce the amount of data that is transferred between client and server.

Background

UpdatePanel controls work by specifying regions of a page that can be updated without refreshing the whole page. This process is coordinated by the ScriptManager server control and the client PageRequestManager class. When partial-page updates are enabled, controls can asynchronously post to the server. An asynchronous postback behaves like a regular postback in that the resulting server page executes the complete page and control life cycle. However, with an asynchronous postback, page updates are limited to regions of the page that are enclosed in UpdatePanel controls and that are marked to be updated. The server sends HTML markup for only the affected elements to the browser. In the browser, the client PageRequestManager class performs Document Object Model (DOM) manipulation to replace existing HTML with updated markup. The following illustration shows a page that is loaded for the first time, and a subsequent asynchronous postback that refreshes the content of an UpdatePanel control.

Comments

Post a Comment

Popular posts from this blog

Asynchronous Socket Programming in C#

Image
Objective The objective of this article is to demonstrate a socket-based client/server application that will allow two-way asynchronous communication between a server and multiple client applications. Because this example uses asynchronous methods, the server application does not use threads to communicate to multiple clients (although internally the asynchronous communication mechanism uses threads at the OS level). The Difference Between Synchronous and Asynchronous Communication in Network Programming The key difference between synchronous and asynchronous communication can be explained with an example. Consider a server application that is listening on a specific port to get data from clients. In synchronous receiving, while the server is waiting to receive data from a client, if the stream is empty the main thread will block until the request for data is satisfied. Hence, the server cannot do anything else until it receives data from the client. If another clien
Read more

Url Routing MVC TUTORIAL

Image
This tutorial covers an introduction to the MVC pattern using Visual Basic. It also includes a brief overview of the URL routing assumptions that are a foundation to the implementation of the pattern. A sample application is created to demonstrate the fundamentals of this new web-application model. Implementing business rules and testing is also covered. Finally, the use of two alternative view engines, Silverlight and XML Literals, is coverd.
Read more

WCF Chat Sample

Image
The Chat sample demonstrates how to implement a multiparty chat application by using PeerChannel. Messages sent by any instance of a chat application are received by all other instances. To get samples and instructions for installing them Do one or more of the following: On the Help menu, click Samples . The Readme displays information about samples. Visit the Visual Studio 2008 Samples Web site. The most recent versions of samples are available there. Locate samples on the computer on which Visual Studio is installed. By default, samples and a Readme file are installed in drive :\Program Files\Microsoft Visual Studio 9.0\Samples\ lcid . For Express editions of Visual Studio, all samples are located online. For more information, see Locating Sample Files . Security Note: This sample code is intended to illustrate a concept, and it shows only the code that is relevant to that concept. It may not meet the security requirements for a specific environment, a
Read more