計(jì)算機(jī)專(zhuān)業(yè)畢業(yè)外文翻譯--asp.net 概述（中文3681字）

1、<p>　　附件1：外文資料翻譯譯文</p><p>　　ASP.NET 概述</p><p>　　ASP.NET 是一個(gè)統(tǒng)一的 Web 開(kāi)發(fā)模型，它包括您使用盡可能少的代碼生成企業(yè)級(jí) Web 應(yīng)用程序所必需的各種服務(wù)。ASP.NET 作為 .NET Framework 的一部分提供。當(dāng)您編寫(xiě) ASP.NET 應(yīng)用程序的代碼時(shí)，可以訪問(wèn) .NET Framework 中的類(lèi)。您可

2、以使用與公共語(yǔ)言運(yùn)行庫(kù) (CLR) 兼容的任何語(yǔ)言來(lái)編寫(xiě)應(yīng)用程序的代碼，這些語(yǔ)言包括 Microsoft Visual Basic、C#、JScript .NET 和 J#。使用這些語(yǔ)言，可以開(kāi)發(fā)利用公共語(yǔ)言運(yùn)行庫(kù)、類(lèi)型安全、繼承等方面的優(yōu)點(diǎn)的 ASP.NET 應(yīng)用程序。</p><p>　　ASP.NET 包括：</p><p><b>　　頁(yè)和控件框架</b>&l

3、t;/p><p>　　ASP.NET 編譯器</p><p><b>　　安全基礎(chǔ)結(jié)構(gòu)</b></p><p><b>　　狀態(tài)管理功能</b></p><p><b>　　應(yīng)用程序配置</b></p><p>　　運(yùn)行狀況監(jiān)視和性能功能</p>

4、<p><b>　　調(diào)試支持</b></p><p>　　XML Web services 框架</p><p>　　可擴(kuò)展的宿主環(huán)境和應(yīng)用程序生命周期管理</p><p><b>　　可擴(kuò)展的設(shè)計(jì)器環(huán)境</b></p><p>　　ASP.NET 頁(yè)和控件框架是一種編程框架，它在 W

5、eb 服務(wù)器上運(yùn)行，可以動(dòng)態(tài)地生成和呈現(xiàn) ASP.NET 網(wǎng)頁(yè)。可以從任何瀏覽器或客戶端設(shè)備請(qǐng)求 ASP.NET 網(wǎng)頁(yè)，ASP.NET 會(huì)向請(qǐng)求瀏覽器呈現(xiàn)標(biāo)記（例如 HTML）。通常，您可以對(duì)多個(gè)瀏覽器使用相同的頁(yè)，因?yàn)?ASP.NET 會(huì)為發(fā)出請(qǐng)求的瀏覽器呈現(xiàn)適當(dāng)?shù)臉?biāo)記。但是，您可以針對(duì)諸如 Microsoft Internet Explorer 6 的特定瀏覽器設(shè)計(jì) ASP.NET 網(wǎng)頁(yè)，并利用該瀏覽器的功能。ASP.NET 支持基

6、于 Web 的設(shè)備（如移動(dòng)電話、手持型計(jì)算機(jī)和個(gè)人數(shù)字助理 (PDA)）的移動(dòng)控件。 </p><p>　　ASP.NET 網(wǎng)頁(yè)是完全面向?qū)ο蟮?。?ASP.NET 網(wǎng)頁(yè)中，可以使用屬性、方法和事件來(lái)處理 HTML 元素。ASP.NET 頁(yè)框架為響應(yīng)在服務(wù)器上運(yùn)行的代碼中的客戶端事件提供統(tǒng)一的模型，從而使您不必考慮基于 Web 的應(yīng)用程序中固有的客戶端和服務(wù)器隔離的實(shí)現(xiàn)細(xì)節(jié)。該框架還會(huì)在頁(yè)處理生命周期中自動(dòng)維護(hù)頁(yè)

7、及該頁(yè)上控件的狀態(tài)。</p><p>　　使用 ASP.NET 頁(yè)和控件框架還可以將常用的 UI 功能封裝成易于使用且可重用的控件。控件只需編寫(xiě)一次，即可用于許多頁(yè)并集成到 ASP.NET 網(wǎng)頁(yè)中。這些控件在呈現(xiàn)期間放入 ASP.NET 網(wǎng)頁(yè)中。</p><p>　　ASP.NET 頁(yè)和控件框架還提供各種功能，以便可以通過(guò)主題和外觀來(lái)控制網(wǎng)站的整體外觀和感覺(jué)。可以先定義主題和外觀，然后在頁(yè)

8、面級(jí)或控件級(jí)應(yīng)用這些主題和外觀。</p><p>　　除了主題外，還可以定義母版頁(yè)，以使應(yīng)用程序中的頁(yè)具有一致的布局。一個(gè)母版頁(yè)可以定義您希望應(yīng)用程序中的所有頁(yè)（或一組頁(yè)）所具有的布局和標(biāo)準(zhǔn)行為。然后可以創(chuàng)建包含要顯示的頁(yè)特定內(nèi)容的各個(gè)內(nèi)容頁(yè)。當(dāng)用戶請(qǐng)求內(nèi)容頁(yè)時(shí)，這些內(nèi)容頁(yè)與母版頁(yè)合并，產(chǎn)生將母版頁(yè)的布局與內(nèi)容頁(yè)中的內(nèi)容組合在一起的輸出。</p><p>　　所有 ASP.NET 代碼都經(jīng)

9、過(guò)了編譯，可提供強(qiáng)類(lèi)型、性能優(yōu)化和早期綁定以及其他優(yōu)點(diǎn)。代碼一經(jīng)編譯，公共語(yǔ)言運(yùn)行庫(kù)會(huì)進(jìn)一步將 ASP.NET 編譯為本機(jī)代碼，從而提供增強(qiáng)的性能。</p><p>　　ASP.NET 包括一個(gè)編譯器，該編譯器將包括頁(yè)和控件在內(nèi)的所有應(yīng)用程序組件編譯成一個(gè)程序集，之后 ASP.NET 宿主環(huán)境可以使用該程序集來(lái)處理用戶請(qǐng)求。</p><p>　　除了 .NET 的安全功能外，ASP.NET

10、 還提供了高級(jí)的安全基礎(chǔ)結(jié)構(gòu)，以便對(duì)用戶進(jìn)行身份驗(yàn)證和授權(quán)，并執(zhí)行其他與安全相關(guān)的功能。您可以使用由 IIS 提供的 Windows 身份驗(yàn)證對(duì)用戶進(jìn)行身份驗(yàn)證，也可以通過(guò)您自己的用戶數(shù)據(jù)庫(kù)使用 ASP.NET Forms 身份驗(yàn)證和 ASP.NET 成員資格來(lái)管理身份驗(yàn)證。此外，可以使用 Windows 組或您自己的自定義角色數(shù)據(jù)庫(kù)（使用 ASP.NET 角色）來(lái)管理 Web 應(yīng)用程序的功能和信息方面的授權(quán)。您可以根據(jù)應(yīng)用程序的需要方

11、便地移除、添加或替換這些方案。</p><p>　　ASP.NET 始終使用特定的 Windows 標(biāo)識(shí)運(yùn)行，因此，您可以通過(guò)使用 Windows 功能（例如 NTFS 訪問(wèn)控制列表 (ACL)、數(shù)據(jù)庫(kù)權(quán)限等等）來(lái)保護(hù)應(yīng)用程序的安全。</p><p>　　ASP.NET 提供了內(nèi)部狀態(tài)管理功能，它使您能夠存儲(chǔ)頁(yè)請(qǐng)求期間的信息，例如客戶信息或購(gòu)物車(chē)的內(nèi)容。您可以保存和管理應(yīng)用程序特定、會(huì)話特

12、定、頁(yè)特定、用戶特定和開(kāi)發(fā)人員定義的信息。此信息可以獨(dú)立于頁(yè)上的任何控件。</p><p>　　ASP.NET 提供了分布式狀態(tài)功能，使您能夠管理一臺(tái)計(jì)算機(jī)或數(shù)臺(tái)計(jì)算機(jī)上同一應(yīng)用程序的多個(gè)實(shí)例的狀態(tài)信息。</p><p>　　通過(guò) ASP.NET 應(yīng)用程序使用的配置系統(tǒng)，可以定義 Web 服務(wù)器、網(wǎng)站或單個(gè)應(yīng)用程序的配置設(shè)置。您可以在部署 ASP.NET 應(yīng)用程序時(shí)定義配置設(shè)置，并且可以隨

13、時(shí)添加或修訂配置設(shè)置，且對(duì)運(yùn)行的 Web 應(yīng)用程序和服務(wù)器具有最小的影響。ASP.NET 配置設(shè)置存儲(chǔ)在基于 XML 的文件中。由于這些 XML 文件是 ASCII 文本文件，因此對(duì) Web 應(yīng)用程序進(jìn)行配置更改比較簡(jiǎn)單。您可以擴(kuò)展配置方案，使其符合自己的要求。</p><p>　　ASP.NET 包括可監(jiān)視 ASP.NET 應(yīng)用程序的運(yùn)行狀況和性能的功能。使用 ASP.NET 運(yùn)行狀況監(jiān)視可以報(bào)告關(guān)鍵事件，這些

14、關(guān)鍵事件提供有關(guān)應(yīng)用程序的運(yùn)行狀況和錯(cuò)誤情況的信息。這些事件顯示診斷和監(jiān)視特征的組合，并在記錄哪些事件以及如何記錄事件等方面提供了高度的靈活性。</p><p>　　ASP.NET 支持兩組可供應(yīng)用程序訪問(wèn)的性能計(jì)數(shù)器：</p><p>　　ASP.NET 系統(tǒng)性能計(jì)數(shù)器組</p><p>　　ASP.NET 應(yīng)用程序性能計(jì)數(shù)器組</p><p&

15、gt;　　ASP.NET 利用運(yùn)行庫(kù)調(diào)試基礎(chǔ)結(jié)構(gòu)來(lái)提供跨語(yǔ)言和跨計(jì)算機(jī)調(diào)試支持?？梢哉{(diào)試托管和非托管對(duì)象，以及公共語(yǔ)言運(yùn)行庫(kù)和腳本語(yǔ)言支持的所有語(yǔ)言。</p><p>　　此外，ASP.NET 頁(yè)框架提供使您可以將檢測(cè)消息插入 ASP.NET 網(wǎng)頁(yè)的跟蹤模式。</p><p>　　ASP.NET 支持 XML Web services。XML Web services 是包含業(yè)務(wù)功能的組件

16、，利用該業(yè)務(wù)功能，應(yīng)用程序可以使用 HTTP 和 XML 消息等標(biāo)準(zhǔn)跨越防火墻交換信息。XML Web services 不用依靠特定的組件技術(shù)或?qū)ο笳{(diào)用約定。因此，用任何語(yǔ)言編寫(xiě)、使用任何組件模型并在任何操作系統(tǒng)上運(yùn)行的程序，都可以訪問(wèn) XML Web services。</p><p>　　ASP.NET 包括一個(gè)可擴(kuò)展的宿主環(huán)境，該環(huán)境控制應(yīng)用程序的生命周期，即從用戶首次訪問(wèn)此應(yīng)用程序中的資源（例如頁(yè)）到應(yīng)

17、用程序關(guān)閉這一期間。雖然 ASP.NET 依賴(lài)作為應(yīng)用程序宿主的 Web 服務(wù)器 (IIS)，但 ASP.NET 自身也提供了許多宿主功能。通過(guò) ASP.NET 的基礎(chǔ)結(jié)構(gòu)，您可以響應(yīng)應(yīng)用程序事件并創(chuàng)建自定義 HTTP 處理程序和 HTTP 模塊。</p><p>　　ASP.NET 中提供了對(duì)創(chuàng)建 Web 服務(wù)器控件設(shè)計(jì)器（用于可視化設(shè)計(jì)工具，例如 Visual Studio）的增強(qiáng)支持。使用設(shè)計(jì)器可以為控件生

18、成設(shè)計(jì)時(shí)用戶界面，這樣開(kāi)發(fā)人員可以在可視化設(shè)計(jì)工具中配置控件的屬性和內(nèi)容。</p><p>　　C# 是一種簡(jiǎn)潔、類(lèi)型安全的面向?qū)ο蟮恼Z(yǔ)言，開(kāi)發(fā)人員可以使用它來(lái)構(gòu)建在 .NET Framework 上運(yùn)行的各種安全、可靠的應(yīng)用程序。使用 C#，您可以創(chuàng)建傳統(tǒng)的 Windows 客戶端應(yīng)用程序、XML Web services、分布式組件、客戶端 - 服務(wù)器應(yīng)用程序、數(shù)據(jù)庫(kù)應(yīng)用程序以及很多其他類(lèi)型的程序。Micro

19、soft Visual C# 2005 提供高級(jí)代碼編輯器、方便的用戶界面設(shè)計(jì)器、集成調(diào)試器和許多其他工具，以在 C# 語(yǔ)言版本 2.0 和 .NET Framework 的基礎(chǔ)上加快應(yīng)用程序的開(kāi)發(fā)。</p><p>　　C# 語(yǔ)法表現(xiàn)力強(qiáng)，只有不到 90 個(gè)關(guān)鍵字，而且簡(jiǎn)單易學(xué)。C# 的大括號(hào)語(yǔ)法使任何熟悉 C、C++ 或 Java 的人都可以立即上手。了解上述任何一種語(yǔ)言的開(kāi)發(fā)人員通常在很短的時(shí)間內(nèi)就可以開(kāi)始

20、使用 C# 高效地工作。C# 語(yǔ)法簡(jiǎn)化了 C++ 的諸多復(fù)雜性，同時(shí)提供了很多強(qiáng)大的功能，例如可為空的值類(lèi)型、枚舉、委托、匿名方法和直接內(nèi)存訪問(wèn)，這些都是 Java 所不具備的。C# 還支持泛型方法和類(lèi)型，從而提供了更出色的類(lèi)型安全和性能。C# 還提供了迭代器，允許集合類(lèi)的實(shí)現(xiàn)者定義自定義的迭代行為，簡(jiǎn)化了客戶端代碼對(duì)它的使用。</p><p>　　作為一種面向?qū)ο蟮恼Z(yǔ)言，C# 支持封裝、繼承和多態(tài)性概念。所有的

21、變量和方法，包括 Main 方法（應(yīng)用程序的入口點(diǎn)），都封裝在類(lèi)定義中。類(lèi)可能直接從一個(gè)父類(lèi)繼承，但它可以實(shí)現(xiàn)任意數(shù)量的接口。重寫(xiě)父類(lèi)中的虛方法的各種方法要求 override 關(guān)鍵字作為一種避免意外重定義的方式。在 C# 中，結(jié)構(gòu)類(lèi)似于一個(gè)輕量類(lèi)；它是一種堆棧分配的類(lèi)型，可以實(shí)現(xiàn)接口，但不支持繼承。</p><p>　　除了這些基本的面向?qū)ο蟮脑?，C# 還通過(guò)幾種創(chuàng)新的語(yǔ)言結(jié)構(gòu)加快了軟件組件的開(kāi)發(fā)，其中包括：

22、</p><p>　　封裝的方法簽名（稱(chēng)為委托），它實(shí)現(xiàn)了類(lèi)型安全的事件通知。</p><p>　　屬性 (Property)，充當(dāng)私有成員變量的訪問(wèn)器。 </p><p>　　屬性 (Attribute)，提供關(guān)于運(yùn)行時(shí)類(lèi)型的聲明性元數(shù)據(jù)。 </p><p>　　內(nèi)聯(lián) XML 文檔注釋。</p><p>　　在 C#

23、 中，如果需要與其他 Windows 軟件（如 COM 對(duì)象或本機(jī) Win32 DLL）交互，可以通過(guò)一個(gè)稱(chēng)為“Interop”的過(guò)程來(lái)實(shí)現(xiàn)?；ゲ僮魇?C# 程序能夠完成本機(jī) C++ 應(yīng)用程序可以完成的幾乎任何任務(wù)。在直接內(nèi)存訪問(wèn)必不可少的情況下，C# 甚至支持指針和“不安全”代碼的概念。</p><p>　　C# 的生成過(guò)程比 C 和 C++ 簡(jiǎn)單，比 Java 更為靈活。沒(méi)有單獨(dú)的頭文件，也不要求按照特定順序

24、聲明方法和類(lèi)型。C# 源文件可以定義任意數(shù)量的類(lèi)、結(jié)構(gòu)、接口和事件。</p><p>　　C# 程序在 .NET Framework 上運(yùn)行，它是 Windows 的一個(gè)必要組件，包括一個(gè)稱(chēng)為公共語(yǔ)言運(yùn)行時(shí) (CLR) 的虛擬執(zhí)行系統(tǒng)和一組統(tǒng)一的類(lèi)庫(kù)。CLR 是 Microsoft 的公共語(yǔ)言基礎(chǔ)結(jié)構(gòu) (CLI) 的一個(gè)商業(yè)實(shí)現(xiàn)。CLI 是一種國(guó)際標(biāo)準(zhǔn)，是用于創(chuàng)建語(yǔ)言和庫(kù)在其中無(wú)縫協(xié)同工作的執(zhí)行和開(kāi)發(fā)環(huán)境的基礎(chǔ)。

25、</p><p>　　用 C# 編寫(xiě)的源代碼被編譯為一種符合 CLI 規(guī)范的中間語(yǔ)言 (IL)。IL 代碼與資源（如位圖和字符串）一起作為一種稱(chēng)為程序集的可執(zhí)行文件存儲(chǔ)在磁盤(pán)上，通常具有的擴(kuò)展名為 .exe 或 .dll。程序集包含清單，它提供關(guān)于程序集的類(lèi)型、版本、區(qū)域性和安全要求等信息。</p><p>　　執(zhí)行 C# 程序時(shí)，程序集將加載到 CLR 中，這可能會(huì)根據(jù)清單中的信息執(zhí)行不

26、同的操作。然后，如果符合安全要求，CLR 執(zhí)行實(shí)時(shí) (JIT) 編譯以將 IL 代碼轉(zhuǎn)換為本機(jī)機(jī)器指令。CLR 還提供與自動(dòng)垃圾回收、異常處理和資源管理有關(guān)的其他服務(wù)。由 CLR 執(zhí)行的代碼有時(shí)稱(chēng)為“托管代碼”，它與編譯為面向特定系統(tǒng)的本機(jī)機(jī)器語(yǔ)言的“非托管代碼”相對(duì)應(yīng)。下圖演示了 C# 源代碼文件、基類(lèi)庫(kù)、程序集和 CLR 的編譯時(shí)與運(yùn)行時(shí)的關(guān)系。</p><p>　　語(yǔ)言互操作性是 .NET Framewor

27、k 的一個(gè)關(guān)鍵功能。因?yàn)橛?C# 編譯器生成的 IL 代碼符合公共類(lèi)型規(guī)范 (CTS)，因此從 C# 生成的 IL 代碼可以與從 Visual Basic、Visual C++、Visual J# 的 .NET 版本或者其他 20 多種符合 CTS 的語(yǔ)言中的任何一種生成的代碼進(jìn)行交互。單一程序集可能包含用不同 .NET 語(yǔ)言編寫(xiě)的多個(gè)模塊，并且類(lèi)型可以相互引用，就像它們是用同一種語(yǔ)言編寫(xiě)的。</p><p>　

28、　除了運(yùn)行時(shí)服務(wù)，.NET Framework 還包含一個(gè)由 4000 多個(gè)類(lèi)組成的內(nèi)容詳盡的庫(kù)，這些類(lèi)被組織為命名空間，為從文件輸入和輸出到字符串操作、到 XML 分析、到 Windows 窗體控件的所有內(nèi)容提供多種有用的功能。典型的 C# 應(yīng)用程序使用 .NET Framework 類(lèi)庫(kù)廣泛地處理常見(jiàn)的“日?！比蝿?wù)。</p><p><b>　　附件2：外文原文</b></p>

29、;<p>　　ASP.NET Overview</p><p>　　ASP.NET is a unified Web development model that includes the services necessary for you to build enterprise-class Web applications with a minimum of coding. ASP.NET is

30、 part of the .NET Framework, and when coding ASP.NET applications you have access to classes in the .NET Framework. You can code your applications in any language compatible with the common language runtime (CLR), includ

31、ing Microsoft Visual Basic, C#, JScript .NET, and J#. These languages enable you to develop ASP.NET applications </p><p>　　ASP.NET includes:</p><p>　　A page and controls framework</p>

32、<p>　　The ASP.NET compiler</p><p>　　Security infrastructure</p><p>　　State-management facilities</p><p>　　Application configuration</p><p>　　Health monitoring an

33、d performance features</p><p>　　Debugging support</p><p>　　An XML Web services framework</p><p>　　Extensible hosting environment and application life cycle management</p><

34、;p>　　An extensible designer environment</p><p>　　The ASP.NET page and controls framework is a programming framework that runs on a Web server to dynamically produce and render ASP.NET Web pages. ASP.NET W

35、eb pages can be requested from any browser or client device, and ASP.NET renders markup (such as HTML) to the requesting browser. As a rule, you can use the same page for multiple browsers, because ASP.NET renders the ap

36、propriate markup for the browser making the request. However, you can design your ASP.NET Web page to target a specific brows</p><p>　　ASP.NET Web pages are completely object-oriented. Within ASP.NET Web pag

37、es you can work with HTML elements using properties, methods, and events. The ASP.NET page framework removes the implementation details of the separation of client and server inherent in Web-based applications by present

38、ing a unified model for responding to client events in code that runs at the server. The framework also automatically maintains the state of a page and the controls on that page during the page processing lif</p>

39、<p>　　The ASP.NET page and controls framework also enables you to encapsulate common UI functionality in easy-to-use, reusable controls. Controls are written once, can be used in many pages, and are integrated into

40、the ASP.NET Web page that they are placed in during rendering.</p><p>　　The ASP.NET page and controls framework also provides features to control the overall look and feel of your Web site via themes and ski

41、ns. You can define themes and skins and then apply them at a page level or at a control level. </p><p>　　In addition to themes, you can define master pages that you use to create a consistent layout for the

42、pages in your application. A single master page defines the layout and standard behavior that you want for all the pages (or a group of pages) in your application. You can then create individual content pages that contai

43、n the page-specific content you want to display. When users request the content pages, they merge with the master page to produce output that combines the layout of the master pa</p><p>　　All ASP.NET code is

44、 compiled, which enables strong typing, performance optimizations, and early binding, among other benefits. Once the code has been compiled, the common language runtime further compiles ASP.NET code to native code, provi

45、ding improved performance.</p><p>　　ASP.NET includes a compiler that will compile all your application components including pages and controls into an assembly that the ASP.NET hosting environment can then u

46、se to service user requests. </p><p>　　In addition to the security features of .NET, ASP.NET provides an advanced security infrastructure for authenticating and authorizing user access as well as performing

47、other security-related tasks. You can authenticate users using Windows authentication supplied by IIS, or you can manage authentication using your own user database using ASP.NET forms authentication and ASP.NET membersh

48、ip. Additionally, you can manage the authorization to the capabilities and information of your Web application u</p><p>　　ASP.NET always runs with a particular Windows identity so you can secure your applica

49、tion using Windows capabilities such as NTFS Access Control Lists (ACLs), database permissions, and so on. For more information on the identity of ASP.NET,</p><p>　　ASP.NET provides intrinsic state managemen

50、t functionality that enables you to store information between page requests, such as customer information or the contents of a shopping cart. You can save and manage application-specific, session-specific, page-specific,

51、 user-specific, and developer-defined information. This information can be independent of any controls on the page.</p><p>　　ASP.NET offers distributed state facilities, which enable you to manage state info

52、rmation across multiple instances of the same application on one computer or on several computers. </p><p>　　ASP.NET applications use a configuration system that enables you to define configuration settings

53、for your Web server, for a Web site, or for individual applications. You can make configuration settings at the time your ASP.NET applications are deployed and can add or revise configuration settings at any time with mi

54、nimal impact on operational Web applications and servers. ASP.NET configuration settings are stored in XML-based files. Because these XML files are ASCII text files, it is simple to </p><p>　　ASP.NET include

55、s features that enable you to monitor health and performance of your ASP.NET application. ASP.NET health monitoring enables reporting of key events that provide information about the health of an application and about er

56、ror conditions. These events show a combination of diagnostics and monitoring characteristics and offer a high degree of flexibility in terms of what is logged and how it is logged. </p><p>　　ASP.NET support

57、s two groups of performance counters accessible to your applications:</p><p>　　The ASP.NET system performance counter group</p><p>　　The ASP.NET application performance counter group</p>

58、<p>　　ASP.NET takes advantage of the run-time debugging infrastructure to provide cross-language and cross-computer debugging support. You can debug both managed and unmanaged objects, as well as all languages suppo

59、rted by the common language runtime and script languages. </p><p>　　In addition, the ASP.NET page framework provides a trace mode that enables you to insert instrumentation messages into your ASP.NET Web pag

60、es. </p><p>　　ASP.NET supports XML Web services. An XML Web service is a component containing business functionality that enables applications to exchange information across firewalls using standards like HT

61、TP and XML messaging. XML Web services are not tied to a particular component technology or object-calling convention. As a result, programs written in any language, using any component model, and running on any operatin

62、g system can access XML Web services. </p><p>　　ASP.NET includes an extensible hosting environment that controls the life cycle of an application from when a user first accesses a resource (such as a page) i

63、n the application to the point at which the application is shut down. While ASP.NET relies on a Web server (IIS) as an application host, ASP.NET provides much of the hosting functionality itself. The architecture of ASP.

64、NET enables you to respond to application events and create custom HTTP handlers and HTTP modules. </p><p>　　ASP.NET includes enhanced support for creating designers for Web server controls for use with a vi

65、sual design tool such as Visual Studio. Designers enable you to build a design-time user interface for a control, so that developers can configure your control's properties and content in the visual design tool. <

66、/p><p>　　Introduction to the C# Language and the .NET Framework  C# is an elegant and type-safe object-oriented language that enables developers to build a wide range of secure and robust applications that

67、 run on the .NET Framework. You can use C# to create traditional Windows client applications, XML Web services, distributed components, client-server applications, database applications, and much, much more. Microsoft Vi

68、sual C# 2005 provides an advanced code editor, convenient user interface designers, </p><p>　　C# syntax is highly expressive, yet with less than 90 keywords, it is also simple and easy to learn. The curly-br

69、ace syntax of C# will be instantly recognizable to anyone familiar with C, C++ or Java. Developers who know any of these languages are typically able to begin working productively in C# within a very short time. C# synta

70、x simplifies many of the complexities of C++ while providing powerful features such as nullable value types, enumerations, delegates, anonymous methods and direct memo</p><p>　　As an object-oriented language

71、, C# supports the concepts of encapsulation, inheritance and polymorphism. All variables and methods, including the Main method, the application's entry point, are encapsulated within class definitions. A class may i

72、nherit directly from one parent class, but it may implement any number of interfaces. Methods that override virtual methods in a parent class require the override keyword as a way to avoid accidental redefinition. In C#,

73、 a struct is like a lightweight cl</p><p>　　In addition to these basic object-oriented principles, C# facilitates the development of software components through several innovative language constructs, includ

74、ing:</p><p>　　Encapsulated method signatures called delegates, which enable type-safe event notifications.</p><p>　　Properties, which serve as accessors for private member variables. </p>

75、<p>　　Attributes, which provide declarative metadata about types at run time. </p><p>　　Inline XML documentation comments.</p><p>　　If you need to interact with other Windows software such

76、 as COM objects or native Win32 DLLs, you can do this in C# through a process called "Interop." Interop enables C# programs to do just about anything that a native C++ application can do. C# even supports point

77、ers and the concept of "unsafe" code for those cases in which direct memory access is absolutely critical.</p><p>　　The C# build process is simple compared to C and C++ and more flexible than in Ja

78、va. There are no separate header files, and no requirement that methods and types be declared in a particular order. A C# source file may define any number of classes, structs, interfaces, and events.</p><p>

79、;　　C# programs run on the .NET Framework, an integral component of Windows that includes a virtual execution system called the common language runtime (CLR) and a unified set of class libraries. The CLR is Microsoft'

80、s commercial implementation of the common language infrastructure (CLI), an international standard that is the basis for creating execution and development environments in which languages and libraries work together seam

81、lessly.</p><p>　　Source code written in C# is compiled into an intermediate language (IL) that conforms to the CLI specification. The IL code, along with resources such as bitmaps and strings, is stored on d

82、isk in an executable file called an assembly, typically with an extension of .exe or .dll. An assembly contains a manifest that provides information on the assembly's types, version, culture, and security requirement

83、s.</p><p>　　When the C# program is executed, the assembly is loaded into the CLR, which might take various actions based on the information in the manifest. Then, if the security requirements are met, the CL

84、R performs just in time (JIT) compilation to convert the IL code into native machine instructions. The CLR also provides other services related to automatic garbage collection, exception handling, and resource management

85、. Code that is executed by the CLR is sometimes referred to as "managed code," in con</p><p>　　Language interoperability is a key feature of the .NET Framework. Because the IL code produced by the

86、C# compiler conforms to the Common Type Specification (CTS), IL code generated from C# can interact with code that was generated from the .NET versions of Visual Basic, Visual C++, Visual J#, or any of more than 20 other

87、 CTS-compliant languages. A single assembly may contain multiple modules written in different .NET languages, and the types can reference each other just as if they were written </p><p>　　In addition to the

88、run time services, the .NET Framework also includes an extensive library of over 4000 classes organized into namespaces that provide a wide variety of useful functionality for everything from file input and output to str

89、ing manipulation to XML parsing, to Windows Forms controls. The typical C# application uses the .NET Framework class library extensively to handle common "plumbing" chores.</p><p>　　出處：本外文資料出自由Russ