ASP.NET AJAX Beta2 版有不少技术文档，虽然园子里面也有不少人在翻译，不过看别人翻译的总还是会错过原文，而且自己阅读这些文档也是学习英语的好方法，为什么要错过呢。所以以后每天翻译一点点就当是练笔吧，虽然有可能很多错误的地方，不过，起步者有错误是难免的，有错误挑出来就好。
      

Introduction

ASP.NET AJAX enables you to perform significant portions of a Web application's page processing in the browser, without requiring a round trip to the server to update the page. The ASP.NET AJAX development technologies integrate ECMAScript (JavaScript) client script libraries with the ASP.NET 2.0 server-based development platform. ASP.NET AJAX builds on the AJAX strategy for building Web applications, which enables you to make calls to Web-based applications from client script. 

ASP.NET AJAX 概要

简介

ASP.NET AJAX使得你能够将浏览器正在处理的Web应用程序的页面的关键的一部分呈现出来，而不需要往返于服务器来刷新页面。ASP.NET AJAX开发技术结合了使用基于服务器的ASP.NET 2.0开发平台的JavaScript客户端脚本库。ASP.NET AJAX构造在用于形成Web应用程序的AJAX策略之上，这些使得你能够从客户端脚本调用基于Web的应用程序。

The ASP.NET AJAX development strategy enables you to build a new breed of Web application that has a number of advantages over traditional Web applications. AJAX-style applications offers:

• Better performance.

• Extensive user interface features.

• Partial-page updating.

• Asynchronous postbacks.

• Browser independence.

为什么使用ASP.NET AJAX?

ASP.NET AJAX开发策略使得你能够构造一种跟传统的Web应用程序相比拥有大量优势的新的一种Web应用程序。AJAX类型的应用程序提供了：

• 更好的性能
• 丰富的用户交互属性
• 局部页面的刷新
• 异步回传
• 浏览器的无关性。

The goal of ASP.NET AJAX is to give you a broad range of application building blocks, with the following aims:

• Helping you create ASP.NET AJAX applications.

• Integrating ASP.NET AJAX client script features with the features of ASP.NET on the server to provide a comprehensive development platform.

ASP.NET AJAX的目标

ASP.NET AJAX的目标是给你一个广阔的应用程序构造模块的范围，达到下面的目标：

• 帮助你创建ASP.NET AJAX应用程序。
• 结合在服务器上的带有ASP.NET属性的ASP.NET AJAX客户端来提供一个全面的开发平台。

Creating AJAX-style Applications with Client Script

AJAX development can be complex. ASP.NET AJAX helps manage this complexity by providing features such as the following:

• A consistent, object-oriented set of APIs for developing in JavaScript.

• A typing and type-reflection framework for client script.

• Automatic browser compatibility, so that you do not have to write code or deploy components to make your applications run in multiple browsers.

• Client-script APIs and components that support rich UI features, which saves you from having to write the extensive code normally required in AJAX-style applications. For example, ASP.NET AJAX provides commonly used behaviors including drag and drop and auto-completion, which you can bind to HTML controls with minimal coding.

• A declarative scripting model for client development that is similar to the declarative syntax for ASP.NET server controls. This can reduce or eliminate complex coding.

使用客户端脚本来创建AJAX 风格的应用程序

AJAX的开发是很复杂的。ASP.NET AJAX通过提供下面的属性来帮助管理这些复杂的开发。

• 一套牢固的面向对象的API用于客户端脚本的开发。
• 一个用于客户端脚本的输入和反射类型的框架
• 自动兼容浏览器，这样你不需要去写代码或者是配置组件来使得你的应用程序能够在其他的成倍增加的浏览器上运行。
• 客户端脚本的API和组件能够支持丰富的UI属性，把你从AJAX风格应用程序中正常情况下需要编写大量的代码的工作中解放出来。例如，ASP.NET AJAX提供了普通的使用行为包括拖，删除和自动完成，这些使得你能够使用更少的代码将将HTML绑定到控件上去。
• 一个公开的模型脚本用于客户端程序开发，这跟用于ASP.NET服务器控件的语法很相似。这样能够减少和去掉复杂的译码。

Integrating Client Scripting with ASP.NET

The second aim of ASP.NET AJAX is to integrate client scripting with ASP.NET server-side development. Rather than focusing all development on only the client or only the server, ASP.NET AJAX provides tools for both, enabling you to handle application tasks wherever it makes the most sense. ASP.NET provides the following server-side features for ASP.NET AJAX applications:

• Web services that are useful to integrate with ASP.NET AJAX applications, such as a profiles service.

• ASP.NET Web server controls that emit the client script needed for ASP.NET AJAX applications. These controls reduce or eliminate the need to learn the ASP.NET AJAX client script APIs and components.

• Integrated development tools such as Visual Studio, which provide a design-time development environment, debugging, statement completion, administration, and other productivity-enhancing features.

结合ASP.NET的客户端脚本程序

ASP.NET AJAX的第二个目标是结合带有ASP.NET服务器端开发的客户端脚本程序。不仅仅是集中于只用客户端或者是只用服务器来开发，ASP.NET AJAX提供了工具用于这两者，使得你能够将任务委托给应用程序，这样产生了大部分的意义。ASP.NET 提供了以下服务器端的属性用于ASP.NET AJAX应用程序：

• Web服务跟ASP.NET AJAX应用程序的结合是很有用的，就象服务简介一样。
• ASP.NET AJAX应用程序需要带有客户端脚本的ASP.NET Web服务。
• 结合了象Visual Studio这样的开发工具，这些提供了一个设计模式的开发环境，带有调试，状态完成，管理和其他提高开发效率的属性。

In its minimal form, an ASP.NET AJAX application consists of a Web application that uses the ASP.NET AJAX client script libraries to call a service or application on a Web server. But for an application with the best development options and tools, you will also want to use the ASP.NET AJAX server components. The complete ASP.NET AJAX architecture consists of both the client script libraries and of server components.

ASP.NET AJAX的体系结构

在他的最小形式的形态下，一个ASP.NET AJAX应用程序包括了一个使用ASP.NET AJAX 客户端脚本库在Web服务器上调用服务和应用程序的Web应用程序。但是对于一个拥有最好的开发选项和工具的应用程序，你将同样会想要使用 ASP.NET AJAX服务组件。完整的ASP.NET AJAX 结构包括了客户端脚本库和服务器组件。

ASP.NET AJAX Server Components

The ASP.NET AJAX server components consist of ASP.NET Web services and ASP.NET server controls. All ASP.NET features are available to ASP.NET AJAX applications.

ASP.NET AJAX also includes server controls that resemble ASP.NET server controls, but emit ASP.NET AJAX client script. ASP.NET AJAX server controls simplify the process of producing ASP.NET AJAX client script, and are suitable for developers who want to focus on server-based development. ASP.NET AJAX includes a complete set of server controls that corresponds closely to the existing ASP.NET server controls, such as controls for buttons, labels, options, text boxes, check boxes, hyperlinks, and validation controls. All of these controls will be integrated into Visual Studio so that you can work with them in a designer just as you can with standard ASP.NET server controls.

ASP.NET AJAX 服务器组件
ASP.NET AJAX服务器组件包括了ASP.NET Web服务跟ASP.NET服务器控件。所有的ASP.NET的属性在ASP.NET AJAX应用程序都是可用的。
ASP.NET AJAX同样包含类似ASP.NET服务器控件的服务器控件但是包含了APS.NET AJAX 客户端脚本。ASP.NET AJAX服务器控件把产生ASP.NET AJAX客户端脚本程序的过程简单化，并且适合于那些想要基于服务器端开发的开发者。ASP.NET AJAX包含了一套完整的服务器控件，非常接近现有的ASP.NET服务器控件，就象那些button,label,option,textbox,checkbox,hyperlink,validation控件一样。所有的这些控件将被集成在Visual Studio上，这样你能够用他们在设计视图中进行开发就象使用其他的标准ASP.NET服务器控件一样

ASP.NET AJAX Client Components

The following diagram illustrates the architecture of the ASP.NET AJAX client script libraries: 

The ASP.NET AJAX client script libraries consist of a number of JavaScript (.js) files that provide features for object-oriented development. This was not previously available to developers in a scripting environment, and it enables a new level of consistency and modularity in client scripting. The following layers are included in the ASP.NET AJAX script libraries:

• A browser compatibility layer. This provides compatibility across most browsers for your ASP.NET AJAX scripts.

• core services, which include a number of extensions to JavaScript, such as classes, namespaces, event handling, inheritance, data types, and object serialization.

• An ASP.NET AJAX base class library, which includes components like string builders and extended error handling.

• A networking layer that handles communication with Web-based services and applications, and managing the asynchronous remote method calls.

• A UI layer that provides a number of ASP.NET AJAX client capabilities: behaviors, ASP.NET AJAX declarative syntax, UI components, and data binding.

• A controls layer that creates ASP.NET AJAX-specific controls for client development. These controls can be data-bound, scripted, bound to ASP.NET AJAX behaviors such as drag and drop, and so on. This layer includes controls such as an auto-completion text box, ordinary form controls, a data-bound listview control, and navigation controls.

ASP.NET AJAX 客户端组件
下面的图表说明了ASP.NET AJAX 客户端脚本库的体系结构：
ASP.NET AJAX客户端脚本库包含了大量的js文件，提供了用于面向对象开发的属性。这在脚本环境下对开发者来说不象以前那样有用，但是他将客户端脚本开发提高到了更健壮和模块化的全新的水平。ASP.NET AJAX脚本库包含了以下几点：

• 一个具有兼容性的浏览层。这个层使你的ASP.NET AJAX脚本程序在大部分的浏览器之间能够兼容。
• 包含了大量JavaScript的核心服务，就象类，命名空间，事件委托，继承，数据类型和其他大量的对象一样。
• 一个ASP.NET AJAX基类库，包含了象String Builder,Error Handing这样的组件。
• 一个网络层，用基于Web的服务和应用程序以及管理异步调用的一些细微的方法进行通讯。
• 一个提供了许多ASP.NET AJAX客户端性能的用户层，象事件，ASP.NET AJAX语法，用户组件以及数据绑定。
• 一个控件层，创建了用于客户端开发的ASP.NET AJAX风格的控件。这些控件能够被数据绑定，被脚本控制，被象拖拽和删除等等这样的ASP.NET AJAX方式创建。这个层包含了自动完成的textbox控件，普通的 form控件，数据绑定的listview控件以及导航控件。

英文版地址：http://ajax.asp.net/docs/overview/default.aspx