ASP.NET AJAX入门系列（1）：概述

经常关注我的Blog的朋友可能注意到了，在我Blog的左边系列文章中，已经移除了对Atlas学习手记系列文章的推荐，因为随着ASP.NET AJAX 1.0 Beta版的发布，它们已经不再适用，为了不继续误导广大朋友，所以不再作为推荐系列文章，如果有需要参考的朋友，可以直接到随笔分类中查看。

ASP.NET AJAX Beta改动如此之大，鉴于又没有很好的中文参考资料，所以决定最近开始写作ASP.NET AJAX入门系列，这个系列我会把ASP.NET AJAX当作一个全新的东西去对待，不再考虑以前的Atlas，把自己对ASP.NET AJAX的研究与大家分享，便于初学的朋友少走一些弯路。对Atlas熟悉的朋友可以推荐看Dflying Chen的《拥抱变化——从Atlas到ASP.NET AJAX系列》，以及老赵的《深入Atlas系列》。由于个人的能力和掌握的程度有限 ，难免出现错误和遗漏的地方，还请大家多多理解和指正。

OK，让我们从这里开始！

一．ASP.NET AJAX组成部分

在ASP.NET AJAX官方网站上有如下三个下载：

1．ASP.NET AJAX：这部分是ASP.NET AJAX的核心部分，包括了核心AJAX类型系统，网络协议层(networking stack)，组件模型，扩展器(extender)基类，以及与ASP.NET集成的服务器端功能(包括广受欢迎的ScriptManager，UpdatePanel，和 Timer控件)。功能列表如下：

服务端功能列表

Asynchronous client-to-server networking

Authentication as a Web service

ControlExtender class

Profile as a Web service

ScriptManager and ScriptManagerProxy controls

Static page methods as Web services

Timer control

UpdatePanel control

UpdateProgress control

客户端功能列表

Authentication for JavaScript

Behavior class

Calling .asmx Web services from JavaScript

Component class

Control class

Debug class

JavaScript Array type extensions

JavaScript Boolean type extensions

JavaScript Error type extensions

JavaScript Number type extensions

JavaScript Object type extensions

JavaScript String type extensions

JSON serialization

Profile for JavaScript

Trace class

2．ASP.NET AJAX “Value-Add”CTP：ASP.NET AJAX社区支持的“增值”CTP部分，包括了以前各个Atlas CTP版本包含的，但并不在完全支持的“核心”1.0 版本内的额外的高级特性。通过进一步的反馈，这些将会逐步稳定的增加到核心1.0中去。功能列表如下：

服务端功能列表

AutoCompleteExtender class

Cross-browser Web Parts drag-and-drop

DragOverlayExtender control

PopupExtender class

客户端功能列表

Actions components

AutoCompleteBehavior class

BatchResponse class

Binding component

Button control

Checkbox control

Click behavior

Counter class

Cross-browser Web Parts

Data control

DragDropList control

DragDropManager component

DraggableListItem control

FadeAnimation component

Floating behavior

Hover behavior

Hyperlink control

Image control

Input control

Label control

Layout behavior

Opacity behavior

Popup behavior

Selector control

ServiceMethodRequest class

Sys.Data and Sys.UI.Data namespaces

Textbox control

Timer control

Validator controls

xml-script support

3．ASP.NET AJAX Control Toolkit：包含了基于ASP.NET AJAX 1.0 版“核心”下载版本的28个非常酷的免费AJAX控件。它是一个开源项目，由微软和非微软开发人员共同开发的，去CodePlex下载代码。

二．安装ASP.NET AJAX

1．在安装ASP.NET AJAX 1.0 Beta之前，需要先卸载以前所有的CTP版本。

2．下载ASP.NET AJAX 1.0 Beta安装包，安装时Microsoft.Web.Extensions.dll程序集将被安装在GAC（Global Assembly Cache）中，所以使用时不需要再在Web站点的Bin文件夹中包括该程序集。

3．下载安装ASP.NET AJAX “Value-Add”CTP和ASP.NET AJAX Control Toolkit。列表如下：

名称	描述
Accordion:	Create efficient UI from multiple panes with this animated control.
AlwaysVisibleControl	Docks a panel to a corner of the browser window and keeps it visible even when the user scrolls.
Animation	Adds powerful, easy to use animations to any element or control.
CascadingDropDown	Easily link drop downs, complete with asynchronous population and no postbacks!
CollapsiblePanel	This extender allows panels on your page to collapse and expand with no code.
ConfirmButton	This extender adds a confirm dialog to any Button, LinkButton, or ImageButton control.
DragPanel	Makes any panel into an object that you can drag around the page.
DropDown	This extender can wrap any control to provide a SharePoint-style drop-down menu that is attached to the control.
DropShadow	This extender adds attractive drop shadows to any control on the page
DynamicPopulate	Replace the contents of a page element with the result of a web-service call.
FilteredTextBox	Restrict the types of input that text boxes will accept.
HoverMenu	Allows UI to pop up next to a control when the mouse hovers over it.
ModalPopup	Allows you to show styled modal UI without using HTML dialogs.
MutuallyExlcusiveCheckBox	By adding a number of checkboxes to the same “Key”, only one checkbox with the specified key can be checked at a time.
NoBot	Applies simple rules to prevent automated bots or scripts from posting to a page.
NumericUpDown	Allow users to easily increase and decrease values using the mouse to scroll through values.
PagingBulletedList	Add paging and sorting to long bulleted lists.
PasswordStrength	Give your users visual cues to help them create secure passwords.
PopupControl	This extender turns any panel into a popup.
Rating	Let your users easily give feedback by rating content with this easy-to-use control.
ReorderList	This control is a full-featured data-bound control that allows its elements to be reordered on the client via drag and drop.
ResizableControl	Allow users to dynamically resize content, right in the browser
RoundedCorners	Rounds the corners of any control for a clean, professional look!
Slider	Adds an elegant scrollbar-like user interface for setting numeric values.
TextBoxWatermark	This extender adds "watermark" prompt text to TextBoxes on the page.
ToggleButton	This extender turns an ASP.NET CheckBox into an image checkbox.
UpdatePanelAnimation	Animates page elements corresponding to hidden postback activity.
ValidatorCallout	This extender enhances the functionality of existing ASP.NET validators.

三．在Visual Studio.NET 2005开发基于ASP.NET AJAX的应用

安装完ASP.NET AJAX后，打开Visual Studio.NET 2005中新建Web Site，在项目模板中会出现一项ASP.NET AJAX-enabled Web site，直接选择它就可以了，如下图：

新建完成的项目中会自动在Web.config中做好相关的配置，并且AJAXExtensionToolbox.dll已经添加到了VS的工具箱中，不需要再手工添加。

概述篇简单的介绍这里，从下一篇开始学习ASP.NET AJAX中的每一项具体的功能。

下篇预告：ASP.NET AJAX入门系列（2）：使用ScriptManager