計算機專業(yè)畢業(yè)設(shè)計外文翻譯----asp.net 網(wǎng)頁概述

1、<p><b>　　外文資料原文</b></p><p>　　ASP.NET Web Pages Overview</p><p>　　You use ASP.NET Web pages as the programmable user interface for your Web application. An ASP.NET Web page prese

2、nts information to the user in any browser or client device and implements application logic using server-side code. </p><p>　　ASP.NET Web pages are: </p><p>　　Based on Microsoft ASP.NET technol

3、ogy, in which code that runs on the server dynamically generates Web page output to the browser or client device. </p><p>　　Compatible with any browser or mobile device. An ASP.NET Web page automatically ren

4、ders the correct browser-compliant HTML for features such as styles, layout, and so on. Alternatively, you can design your ASP.NET Web pages to run on a specific browser such as Microsoft Internet Explorer 6 and take adv

5、antage of browser-specific features. </p><p>　　Compatible with any language supported by the .NET common language runtime, including Microsoft Visual Basic, Microsoft Visual C#, Microsoft

6、 J#, and Microsoft JScript .NET. </p><p>　　Built on the Microsoft .NET Framework. This provides all the benefits of the framework, including a managed environment, type safety, and inheritance. <

7、;/p><p>　　Flexible because you can add user-created and third party controls to them. </p><p>　　Components of ASP.NET Web Pages </p><p>　　In ASP.NET Web pages, user interface programmi

8、ng is divided into two pieces: the visual component and the logic. If you have worked with tools like Visual Basic and Visual C++ in the past, you will recognize this division between the visible portion of a page and th

9、e code behind the page that interacts with it. </p><p>　　The visual element consists of a file containing static markup such as HTML or ASP.NET server controls or both. The ASP.NET Web page works as a contai

10、ner for the static text and controls you want to display. </p><p>　　The logic for the ASP.NET Web page consists of code that you create to interact with the page. The code can reside either in a script block

11、 in the page or in a separate class. If the code is in a separate class file, this file is referred to as the code-behind file. The code in the code-behind file can be written in Visual Basic, Visual C#, Visual

12、 J#, or JScript .NET. For more information about how ASP.NET Web pages are constructed, see ASP.NET Web Page Code Model. </p><p>　　ASP.NET Web pages are compiled into a dynamic-link library (.dll) file.

13、 The first time a user browses to the .aspx page, ASP.NET automatically generates a .NET class file that represents the page and then compiles it. The .dll file runs on the server and dynamically produces the HTML output

14、 for your page. For more information on how ASP.NET applications are compiled, see ASP.NET Compilation Overview. </p><p>　　What ASP.NET Web Pages Help You Accomplish </p><p>　　Web application pr

15、ogramming presents challenges that do not typically arise when programming traditional client-based applications. Among the challenges are: </p><p>　　Implementing a rich Web user interface   I

16、t can be difficult and tedious to design and implement a user interface using basic HTML facilities, especially if the page has a complex layout, a large amount of dynamic content, and full-featured user-interactive obje

17、cts. </p><p>　　Separation of client and server   In a Web application, the client (browser) and server are different programs often running on different computers (and even on different operat

18、ing systems). Consequently, the two halves of the application share very little information; they can communicate, but typically exchange only small chunks of simple information. </p><p>　　Stateless executio

19、n   When a Web server receives a request for a page, it finds the page, processes it, sends it to the browser, and then discards all page information. If the user requests the same page again, the server r

20、epeats the entire sequence, reprocessing the page from scratch. Put another way, a server has no memory of pages that it has processed—page are stateless. Therefore, if an application needs to maintain information about

21、a page, its stateless nature can become a problem. </p><p>　　Unknown client capabilities    In many cases, Web applications are accessible to many users using different browsers. Browsers

22、 have different capabilities, making it difficult to create an application that will run equally well on all of them. </p><p>　　Complications with data access   Reading from and writing to a d

23、ata source in traditional Web applications can be complicated and resource-intensive. </p><p>　　Complications with scalability   In many cases Web applications designed with existing methods f

24、ail to meet scalability goals due to the lack of compatibility between the various components of the application. This is often a common failure point for applications under a heavy growth cycle. </p><p>　　M

25、eeting these challenges for Web applications can require substantial time and effort. ASP.NET Web pages and the ASP.NET page framework address these challenges in the following ways: </p><p>　　Intuitive, con

26、sistent object model   The ASP.NET page framework presents an object model that enables you to think of your forms as a unit, not as separate client and server pieces. In this model, you can program the pa

27、ge in a more intuitive way than in traditional Web applications, including the ability to set properties for page elements and respond to events. In addition, ASP.NET server controls are an abstraction from the physical

28、contents of an HTML page and from the direct interaction betw</p><p>　　Event-driven programming model   ASP.NET Web pages bring to Web applications the familiar model of writing event handlers

29、 for events that occur on either the client or server. The ASP.NET page framework abstracts this model in such a way that the underlying mechanism of capturing an event on the client, transmitting it to the server, and c

30、alling the appropriate method is all automatic and invisible to you. The result is a clear, easily written code structure that supports event-driven developmen</p><p>　　Intuitive state management  

31、 The ASP.NET page framework automatically handles the task of maintaining the state of your page and its controls, and it provides you with explicit ways to maintain the state of application-specific information. Th

32、is is accomplished without heavy use of server resources and can be implemented with or without sending cookies to the browser. </p><p>　　Browser-independent applications   The ASP.NET page fr

33、amework enables you to create all application logic on the server, eliminating the need to explicitly code for differences in browsers. However, it still enables you to take advantage of browser-specific features by writ

34、ing client-side code to provide improved performance and a richer client experience. </p><p>　　NET Framework common language runtime support  The ASP.NET page framework is built on the .NET Framewo

35、rk, so the entire framework is available to any ASP.NET application. Your applications can be written in any language that is compatible that is with the runtime. In addition, data access is simplified using the data acc

36、ess infrastructure provided by the .NET Framework, including ADO.NET. </p><p>　　NET Framework scalable server performance The ASP.NET page framework enables you to scale your Web application from one co

37、mputer with a single processor to a multi-computer Web farm cleanly and without complicated changes to the application's logic.</p><p><b>　　翻譯文稿</b></p><p>　　ASP.NET 網(wǎng)頁概述</p&g

38、t;<p>　　可以使用 ASP.NET 網(wǎng)頁作為 Web 應(yīng)用程序的可編程用戶接口。ASP.NET 網(wǎng)頁在任何瀏覽器或客戶端設(shè)備中向用戶提供信息，并使用服務(wù)器端代碼來實現(xiàn)應(yīng)用程序邏輯。</p><p>　　ASP.NET 網(wǎng)頁有下列特點：</p><p>　　基于 Microsoft ASP.NET 技術(shù)。在該技術(shù)中，在服務(wù)器上運行的代碼動態(tài)地生成到瀏覽器或客戶端設(shè)備的網(wǎng)頁

39、輸出。</p><p>　　兼容所有瀏覽器或移動設(shè)備。ASP.NET 網(wǎng)頁自動為樣式、布局等功能呈現(xiàn)正確的、符合瀏覽器的 HTML。此外，您還可以將 ASP.NET 網(wǎng)頁設(shè)計為在特定瀏覽器（如 Microsoft Internet Explorer 6）上運行并利用瀏覽器特定的功能。</p><p>　　兼容 .NET 公共語言運行時所支持的任何語言，其中包括 Microsoft Visu

40、al Basic、Microsoft Visual C#、Microsoft J# 和 Microsoft JScript .NET。</p><p>　　基于 Microsoft .NET Framework 生成。它提供了 Framework 的所有優(yōu)點，包括托管環(huán)境、類型安全性和繼承。</p><p>　　具有靈活性，因為您可以向它們添加用戶創(chuàng)建的控件和第三方控件。</p>

41、;<p>　　ASP.NET 網(wǎng)頁的組件 </p><p>　　在 ASP.NET 網(wǎng)頁中，用戶界面編程分為兩個部分：可視組件和邏輯。如果您以前使用過類似于 Visual Basic 和 Visual C++ 的工具，您將認(rèn)同在頁的可視部分和頁后與之交互的代碼之間存在這樣一種劃分。</p><p>　　可視元素由一個包含靜態(tài)標(biāo)記（例如 HTML 或 ASP.NET 服務(wù)器控件

42、或兩者）的文件組成。ASP.NET 網(wǎng)頁用作要顯示的靜態(tài)文本和控件的容器。</p><p>　　ASP.NET 網(wǎng)頁的邏輯由代碼組成，這些代碼由您創(chuàng)建以與頁進行交互。代碼可以駐留在頁的 script 塊中或者單獨的類中。如果代碼在單獨的類文件中，則該文件稱為“代碼隱藏”文件。代碼隱藏文件中的代碼可以使用 Visual Basic、 Visual C#、Visual J# 或 JScript .NET 編寫。有關(guān)如

43、何構(gòu)建 ASP.NET 網(wǎng)頁的更多信息，請參見 ASP.NET 網(wǎng)頁代碼模型。</p><p>　　ASP.NET 網(wǎng)頁編譯為動態(tài)鏈接庫 (.dll) 文件。用戶第一次瀏覽到 .aspx 頁時，ASP.NET 自動生成表示該頁的 .NET 類文件，然后編譯此文件。.dll 文件在服務(wù)器上運行，并動態(tài)生成頁的 HTML 輸出。有關(guān)如何編譯 ASP.NET 應(yīng)用程序的更多信息，請參見 ASP.NET 編譯概述。<

44、;/p><p>　　ASP.NET 網(wǎng)頁幫助您完成哪些任務(wù) </p><p>　　Web 應(yīng)用程序編程帶來了一些特殊的難題，在對傳統(tǒng)的基于客戶端的應(yīng)用程序進行編程時，通常不會遇到這些難題。這些難題包括：</p><p>　　實現(xiàn)多樣式的 Web 用戶界面使用基本的 HTML 功能來設(shè)計和實現(xiàn)用戶接口既困難又費事，特別是在頁具有復(fù)雜布局且包含大量動態(tài)內(nèi)容和功能齊全的用戶交

45、互對象時。</p><p>　　客戶端與服務(wù)器的分離在 Web 應(yīng)用程序中，客戶端（瀏覽器）和服務(wù)器是不同的程序，它們通常在不同的計算機（甚至不同的操作系統(tǒng)）上運行。因此，共同組成應(yīng)用程序的這兩個部分僅共享很少的信息；它們可以進行通信，但通常只交換很小塊的簡單信息。</p><p>　　無狀態(tài)執(zhí)行當(dāng) Web 服務(wù)器接收到對某頁的請求時，會找到該頁，對其進行處理，將其發(fā)送到瀏覽器，然后丟棄所

46、有頁信息。如果用戶再次請求同一頁，服務(wù)器則會重復(fù)整個過程：從頭 開始對該頁進行重新處理。換言之，服務(wù)器不會記憶它已處理的頁，頁是無狀態(tài)的。因此，如果應(yīng)用程序需要維護有關(guān)某頁的信息，其無狀態(tài)的性質(zhì)就成為了一個問題。</p><p>　　未知的客戶端功能在許多情況下，Web 應(yīng)用程序可供許多使用不同瀏覽器的用戶進行訪問。瀏覽器具有不同的功能，因此很難創(chuàng)建將在所有瀏覽器上都同樣正常運行的應(yīng)用程序。</p>

47、<p>　　數(shù)據(jù)訪問方面的復(fù)雜性對位于傳統(tǒng) Web 應(yīng)用程序中的數(shù)據(jù)源進行讀取和寫入非常復(fù)雜，并且會消耗大量資源。</p><p>　　可縮放性方面的復(fù)雜性在許多情況下，由于應(yīng)用程序的不同組件之間缺乏兼容性，導(dǎo)致用現(xiàn)有方法設(shè)計的 Web 應(yīng)用程序未能實現(xiàn)可伸縮性的目標(biāo)。對于發(fā)展周期較短的應(yīng)用程序，這往往是一個常見的導(dǎo)致失敗的方面。</p><p>　　若要解決這些 Web 應(yīng)用

48、程序的難題，可能需要大量的時間和精力。ASP.NET 網(wǎng)頁和 ASP.NET 頁框架通過以下幾個方面來處理這些難題：</p><p>　　直觀、一致的對象模型 ASP.NET 頁框架提供了一種對象模型，它使您能夠?qū)⒋绑w當(dāng)作一個整體，而不是分離的客戶端和服務(wù)器模塊。在此模型中，您可以通過比在傳統(tǒng) Web 應(yīng)用程序中更為直觀的方式來對頁進行編程，其中包括能夠設(shè)置頁元素的屬性和響應(yīng)事件。此外，ASP.NET 服務(wù)器控件

49、是基于 HTML 頁的物理內(nèi)容以及瀏覽器與服務(wù)器之間的直接交互的一種抽象模型。通常，您可以按照在客戶端應(yīng)用程序中使用控件的方式使用服務(wù)器控件，而不必考慮如何創(chuàng)建 HTML 來顯示和處理控件及其內(nèi)容。</p><p>　　事件驅(qū)動的編程模型 ASP.NET 網(wǎng)頁為 Web 應(yīng)用程序帶來了一種您熟悉的模型，該模型用于為客戶端或服務(wù)器上發(fā)生的事件編寫事件處理程序。ASP.NET 頁框架對此模型進行了抽象，使捕獲客戶端上

50、的事件、將其傳輸?shù)椒?wù)器并調(diào)用適當(dāng)方法等操作的基礎(chǔ)機制都是自動的，并對于您都是不可見的。這樣就得到了一個 清晰的、易于編寫的、支持事件驅(qū)動開發(fā)的代碼結(jié)構(gòu)。</p><p>　　直觀的狀態(tài)管理 ASP.NET 頁框架會自動處理頁及其控件的狀態(tài)維護任務(wù)，它使您能夠以顯式方式維護應(yīng)用程序特定信息的狀態(tài)。這種狀態(tài)管理無需使用大量服務(wù)器資源即可實現(xiàn)，而且可以通過向瀏覽器發(fā)送 Cookie 來實現(xiàn)，也可以不通過向瀏覽器發(fā)送

51、Cookie 來實現(xiàn)。</p><p>　　獨立于瀏覽器的應(yīng)用程序 ASP.NET 頁框架允許您在服務(wù)器上創(chuàng)建所有應(yīng)用程序邏輯，而無需針對瀏覽器之間的差異進行顯式編碼。但是，它仍允許您利用瀏覽器特定的功能，方法是通過編寫客戶端代碼來提供增強的性能和更豐富的客戶端體驗。</p><p>　　NET Framework 公共語言運行時支持ASP.NET 頁框架是在 .NET Framework

52、 的基礎(chǔ)上生成的，因此整個框架可用于任何 ASP.NET 應(yīng)用程序。您的應(yīng)用程序可以用與運行時兼容的任何語言編寫。此外，數(shù)據(jù)訪問通過 .NET Framework 提供的數(shù)據(jù)訪問基礎(chǔ)結(jié)構(gòu)（包括 ADO.NET）得到了簡化。</p><p>　　NET Framework 可縮放服務(wù)器性能 ASP.NET 頁框架使您能夠?qū)?Web 應(yīng)用程序從一臺只裝有一個處理器的計算機有效地縮放到多計算機“網(wǎng)絡(luò)場”并且無需對應(yīng)用程