ASPNET和NET-Framework毕业论文外文文献翻译及原文

　　毕 业 设 计（论文）

　　外 文 文 献 翻 译

　　文献、资料中文题目：http://www.wendangwang.com 和 .NET Framework 文献、资料英文题目：http://www.wendangwang.com and the .NET Framework 文献、资料来源：

　　文献、资料发表（出版）日期：

　　院 （部）：

　　专 业：

　　班 级：

　　姓 名：

　　学 号：

　　指导教师：

　　翻译日期： 2017.02.14

　　http://www.wendangwang.com and the .NET Framework

　　http://www.wendangwang.com is part of Microsoft's overall .NET framework, which contains a vast set of programming classes designed to satisfy any conceivable programming need. In the following two sections, you learn how http://www.wendangwang.com fits within the .NET framework, and you learn about the languages you can use in your http://www.wendangwang.com pages.

　　The .NET Framework Class Library

　　Imagine that you are Microsoft. Imagine that you have to support multiple programming languages—such as Visual Basic, JScript, and C++. A great deal of the functionality of these programming

　　languages overlaps. For example, for each language, you would have to include methods for accessing the file system, working with databases, and manipulating strings.

　　Furthermore, these languages contain similar programming

　　constructs. Every language, for example, can represent loops and conditionals. Even though the syntax of a conditional written in Visual Basic differs from the syntax of a conditional written in C++, the programming function is the same.

　　Finally, most programming languages have similar variable data types. In most languages, you have some means of representing strings and integers, for example. The maximum and minimum size of an integer might depend on the language, but the basic data type is the same.

　　Maintaining all this functionality for multiple languages requires a lot of work. Why keep reinventing the wheel? Wouldn't it be easier to create all this functionality once and use it for every language?

　　The .NET Framework Class Library does exactly that. It consists of a vast set of classes designed to satisfy any conceivable programming need. For example, the .NET framework contains classes for handling database access, working with the file system, manipulating text, and generating graphics. In addition, it contains more specialized classes for performing tasks such as working with regular expressions and handling network protocols.

　　The .NET framework, furthermore, contains classes that represent all the basic variable data types such as strings, integers, bytes, characters, and arrays.

　　Most importantly, for purposes of this book, the .NET Framework Class Library contains classes for building http://www.wendangwang.com pages. You need to understand, however, that you can access any of the .NET framework classes when you are building your http://www.wendangwang.com pages. Understanding Namespaces

　　As you might guess, the .NET framework is huge. It contains

　　thousands of classes (over 3,400). Fortunately, the classes are not simply jumbled together. The classes of the .NET framework are organized into a hierarchy of namespaces.

　　ASP Classic Note

　　In previous versions of Active Server Pages, you had access to only five standard classes (the Response, Request, Session, Application, and Server objects). http://www.wendangwang.com, in contrast, provides you with access to over 3,400 classes!

　　A namespace is a logical grouping of classes. For example, all the classes that relate to working with the file system are gathered together into the System.IO namespace.

　　The namespaces are organized into a hierarchy (a logical tree). At the root of the tree is the System namespace. This namespace contains all the classes for the base data types, such as strings and arrays. It also contains classes for working with random numbers and dates and times.

　　You can uniquely identify any class in the .NET framework by using the full namespace of the class. For example, to uniquely refer to the class that represents a file system file (the File class), you would use the following:

　　System.IO.File

　　System.IO refers to the namespace, and File refers to the particular class.

　　NOTE

　　You can view all the namespaces of the standard classes in the .NET Framework Class Library by viewing the Reference Documentation for the .NET Framework.

　　Standard http://www.wendangwang.com Namespaces

　　The classes contained in a select number of namespaces are available in your http://www.wendangwang.com pages by default. (You must explicitly import other namespaces.) These default namespaces contain classes that you use most often in your http://www.wendangwang.com applications:

　　? System— Contains all the base data types and other useful classes such as those related to generating random numbers and working with dates and times.

　　System.Collections— Contains classes for working with standard collection types such as hash tables, and array lists.

　　System.Collections.Specialized— Contains classes that

　　represent specialized collections such as linked lists and string collections.

　　System.Configuration— Contains classes for working with

　　configuration files (Web.config files).

　　System.Text— Contains classes for encoding, decoding, and

　　manipulating the contents of strings.

　　System.Text.RegularExpressions— Contains classes for

　　performing regular expression match and replace operations.

　　System.Web— Contains the basic classes for working with the World Wide Web, including classes for representing browser requests and server responses.

　　System.Web.Caching— Contains classes used for caching the

　　content of pages and classes for performing custom caching operations.

　　System.Web.Security— Contains classes for implementing

　　authentication and authorization such as Forms and Passport authentication.

　　System.Web.SessionState— Contains classes for implementing session state.

　　System.Web.UI— Contains the basic classes used in building the user interface of http://www.wendangwang.com pages. ? ? ? ? ? ? ? ? ? ?

　　? System.Web.UI.HTMLControls— Contains the classes for the HTML

　　controls.

　　System.Web.UI.WebControls— Contains the classes for the Web

　　controls. ?

　　.NET Framework-Compatible Languages

　　For purposes of this book, you will write the application logic for your http://www.wendangwang.com pages using Visual Basic as your programming language. It is the default language for http://www.wendangwang.com pages (and the most popular programming language in the world). Although you stick to Visual Basic in this book, you also need to understand that you can create http://www.wendangwang.com pages by using any language that supports the .NET Common Language Runtime. Out of the box, this includes C#

　　(pronounced See Sharp), http://www.wendangwang.com (the .NET version of JavaScript), and the Managed Extensions to C++.

　　NOTE

　　The CD included with this book contains C# versions of all the code samples.

　　Dozens of other languages created by companies other than Microsoft have been developed to work with the .NET framework. Some

　　examples of these other languages include Python, SmallTalk, Eiffel, and COBOL. This means that you could, if you really wanted to, write http://www.wendangwang.com pages using COBOL.

　　Regardless of the language that you use to develop your http://www.wendangwang.com pages, you need to understand that http://www.wendangwang.com pages are compiled before they are executed. This means that http://www.wendangwang.com pages can execute very quickly.

　　The first time you request an http://www.wendangwang.com page, the page is compiled into a .NET class, and the resulting class file is saved beneath a special directory on your server named Temporary http://www.wendangwang.com Files. For each and every http://www.wendangwang.com page, a corresponding class file appears in the Temporary http://www.wendangwang.com Files directory. Whenever you request the same http://www.wendangwang.com page in the future, the corresponding class file is executed. When an http://www.wendangwang.com page is compiled, it is not compiled directly into machine code. Instead, it is compiled into an intermediate-level language called Microsoft Intermediate Language (MSIL).

　　All .NET-compatible languages are compiled into this intermediate language.

　　An http://www.wendangwang.com page isn't compiled into native machine code until it is actually requested by a browser. At that point, the class file contained in the Temporary http://www.wendangwang.com Files directory is compiled with the .NET framework Just in Time (JIT) compiler and executed.

　　The magical aspect of this whole process is that it happens

　　automatically in the background. All you have to do is create a text file with the source code for your http://www.wendangwang.com page, and the .NET framework handles all the hard work of converting it into compiled code for you. ASP CLASSIC NOTE

　　What about VBScript? Before http://www.wendangwang.com, VBScript was the most popular language for developing Active Server Pages.

　　http://www.wendangwang.com does not support VBScript, and this is good news. Visual Basic is a superset of VBScript, which means that Visual Basic has all the functionality of VBScript and more. So, you have a richer set of functions and statements with Visual Basic.

　　Furthermore, unlike VBScript, Visual Basic is a compiled language. This means that if you use Visual Basic to rewrite the same code that you wrote with VBScript, you can get better performance.

　　If you have worked only with VBScript and not Visual Basic in the past, don't worry. Since VBScript is so closely related to Visual Basic, you'll find it easy to make the transition between the two languages. NOTE Microsoft includes an interesting tool named the IL

　　Disassembler (ILDASM) with the .NET framework. You can use this tool to view the disassembled code for any of the http://www.wendangwang.com classes in the Temporary http://www.wendangwang.com Files directory. It lists all the methods and properties of the class and enables you to view the intermediate-level code.

　　This tool also works with all the http://www.wendangwang.com controls discussed in this chapter. For example, you can use the IL Disassembler to view the intermediate-level code for the TextBox control (located in a file named System.Web.dll).