ASP简介毕业论文外文翻译.doc

Brief Introduction Of ASP Craig A. VanLengen, Flagstaff, AZ John D. Haney.Brief Introduction Of ASPJ.Journal of Computing Sciences in Colleges archive.2004,20(1)342-356.Active Server Pages (ASP) is a proven, well-established technology for building dynamic Web applications, which provides the power and flexibility you need to create anything from a personal, Web based photo gallery to a complete catalogue and shopping cart system for your next eCommerce project。 One unique feature of ASP is that it lets you choose your favourite scripting language, be it JavaScript or VBScript; however, VBScript is by far the most popular choice. In this article, I'll bring you up to speed on the basic syntax of the VBScript language, including variables, operators, and control structures.Server-Side ScriptingTo understand where ASP fits into the big picture of Web development, you need to understand the concept of a server-side scripting language. If you've programmed Web pages in Perl, PHP, JSP, or Cold Fusion before, you can safely skip this section all of those are server-side scripting languages, and ASP works in much the same way. If you're coming to ASP armed only with knowledge of HTML (and perhaps with some CSS and/or JavaScript experience) then you'll find that server-side scripting is quite a bit different.Let me begin by giving you a quick review of how standard, non-ASP Web pages work. As shown in Figure 1, the Web browser on the client computer (the computer belonging to the user) makes a request for a page, say file.html (1). Assuming the requested file exists on the Web host computer where the Web Server software can find it, that software replies to the request by sending the file back to the browser (2). Any additional files (images, for example) required to display the page are requested and received in the same way. The protocol used for this exchange, and indeed for all communication between Web browsers and Web servers is called Hypertext Transfer Protocol (HTTP).If you've ever used any JavaScript in your pages, you know that the requested Web page (file.html) can contain, in addition to plain HTML code, small programs written in JavaScript. These programs, or scripts, are read and executed by the Web browser while the page is displayed in the browser. So the Web browser must understand not only how to read HTML and display text.and images, but it must also be able to run JavaScript programs appearing inside Web pages. This arrangement, where the Web browser runs the script after receiving it from the Web server, is called client-side scripting. The name makes sense all of the script runs on the client-side the right-hand side of Figure 1. The Web server is completely oblivious to whether the file it is sending contains a script or not; its all up to the browser (the client) to handle execution of the script.ASP fits into a different category of technologies, called server-side scripting, where it is no longer the browser running on the client that is responsible for running the script; instead, it is the Web server that runs the script. This process is illustrated in Figure 2. As before, the Web browser requests a file (1). In this case, however, the filename ends with .asp (file.asp, for example), branding it as a file containing an ASP script that needs to be processed by the server. The server recognizes this, and instead of directly sending the requested file back to the browser, it sends the file to the ASP scripting engine (2). The engine is a component of the Web server software that can interpret ASP scripts and output the results as HTML. The trick here is that any given script can output different HTML each time it is run, so what comes out of the ASP engine can be different for each client (browser) request. That dynamically generated page is then sent to the browser in response to its request (3), in exactly the same way as the static page was sent in the previous example.Just as when the page contained client-side JavaScript and the server was completely unaware of this fact, when the page contains server-side ASP script, the browser does not know this at all. The ASP code contained in the page is interpreted and converted to plain HTML by the ASP engine before the browser gets to see it; so as far as the browser is concerned an ASP page looks just like any normal Web page. All the work is done on the server-side; thus the name, server-side scripting.附录2：外文文献中文译文ASP简介ASP是构建动态网页应用的被实践证明了的技术，为你需要创建任何的东西从一个基于图片库个人网页到一个完整的目录，为你的下一个商业项目提供全面的系统提供了强大的功能和灵活性。ASP唯一的特性即让你选择你最喜欢的脚本语言，像JavaScript 或者VBScript，然而VBScript是至今为止最流行的脚本语言。在本文中，我将带你学习VBScript的基本syntax，包括变量，操作数和控制结构。服务器端的脚本为了理解ASP适合Web开发的大图片，你需要理解服务器端的脚本语言的概念。如果你用Perl, PHP, JSP 或者Cold Fusion编写Web页面前，你能够安全略过这部分所有这些是服务器端的脚本语言，ASP工作在许多相同的方式。如果你只是用HTML知识来辅助ASP(也许有过一些CSS或者Java脚本的经历),那么你将发现服务器端的脚本是有点不同之处的。 让我开始给你一个标准的快速回顾，非ASP Web网页工作。图1中显示客户端的计算机（计算机属于用户）Web浏览器对页面做请求即html (1)文件。假定在Web主机上存在被请求的文件，Web服务器软件能发现它，软件能通过发回文件给浏览器来回应请求。任何附加文件（如图象文件）要求显示页面是用同样的方式请求和接收。协议用做交易，的确Web浏览器和Web服务器通信是叫做HTTP。如果你曾经在你的网页上用过Java脚本，你知道请求Web网页（html文件）能包含除了普通HTML代码，用Java脚本写的小程序。这些程序或者脚本通过Web浏览器是可读可执行的当页面显示在浏览器上时。所以Web浏览器必须理解怎么读HTML和显示文本和图象，但是它必须能运行显示在Web页面的Java脚本程序。浏览器收到Web服务器这个安排后运行脚本，这个安排叫客户端脚本。在图1右手边所有名字有意义的脚本在客护端运行。Web服务器文件发送是否包含脚本是完全健忘的，这是浏览器（客户端）处理执行脚本。ASP适合不同的技术种类，叫客户端脚本，它不在浏览器运行客户端而是在Web服务器上负责运行脚本。这个过程在图2中描绘。 像前面一样，Web浏览器请求文件（1）然而在这样的情况下，文件名末尾用asp（如文件asp），标志着这个文件包含ASP脚本需要服务器来处理。服务器认识这个，代替直接送请求文件给浏览器，它送文件给ASP脚本引擎（2）引擎是Web服务器的重要软件，它能够解释ASP脚本和作为HTML输出结果。这里的诀窍是任何已给的脚本每次运行能输出不同的HTML，所以ASP引擎的出现能对每一个客户（浏览器）请求是不同的。那动态生成的网页被送到浏览器以响应它的请求，这跟以前的静态网页有相同的方式。正象页面包含客户端的Java脚本和服务器是完全没有意识到这个事实，当页面包含服务器端的ASP脚本，浏览器是根本不知道的。ASP代码包含在页面被解释和传送到ASP页面看起来像其它任何普通的Web页面。所有的工作在服务器端，所以名字就是服务器端脚本。