【正文】 site may also have its own database. The latter is based on all kinds of different operating systems used Web server software installation and debugging. This stage is the whole process of the most important and most timeconsuming part. When we pleted the work, the need for website released. At this stage of the production on the website drawing to a close, the main task is to do a good job in the website release to the work, the web site for final modifications, testing, homepage can guarantee normal operation of the work. Published in the website after website to deal with various aspects of the tests, including the possibility of any different web browsers, different visitors have shown normal, ASP, JSP, PHP normal procedure can work, and so on. This stage is the website of trial operation period, the website at this time should be to make up for various shortings, the website will be more perfected. After a period of operation, the site entered the normal operation period, the main task is to update outdated information website, the visitor39。s properties and content in the visual design tool. Introduction to the C Language and the .NET Framework C is an elegant and typesafe objectoriented language that enables developers to build a wide range of secure and robust applications that run on the .NET Framework. You can use C to create traditional Windows client applications, XML Web services, distributed ponents, clientserver applications, database applications, and much, much more. Microsoft Visual C 2021 provides an advanced code editor, convenient user interface designers, integrated debugger, and many other tools to facilitate rapid application development based on version of the C language and the .NET Framework. Note The Visual C documentation assumes that you have an understanding of basic programming concepts. If you are a plete beginner, you might want to explore Visual C Express Edition, which is available on the Web. You can also take advantage of any of several excellent books and Web resources on C to learn practical programming skills. 18 C syntax is highly expressive, yet with less than 90 keywords, it is also simple and easy to learn. The curlybrace 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 syntax simplifies many of the plexities of C++ while providing powerful features such as nullable value types, enumerations, delegates, anonymous methods and direct memory access, which are not found in Java. C also supports generic methods and types, which provide increased type safety and performance, and iterators, which enable implementers of collection classes to define custom iteration behaviors that are simple to use by client code. As an objectoriented language, C supports the concepts of encapsulation, inheritance and polymorphism. All variables and methods, including the Main method, the application39。 it is a stackallocated type that can implement interfaces but does not support inheritance. In addition to these basic objectoriented principles, C facilitates the development of software ponents through several innovative language constructs, including: ? Encapsulated method signatures called delegates, which enable typesafe event notifications. ? Properties, which serve as accessors for private member variables. ? Attributes, which provide declarative metadata about types at run time. ? Inline XML documentation ments. If you need to interact with other Windows software such as COM objects or native Win32 DLLs, you can do this in C through a process called Interop. Interop 19 enables C programs to do just about anything that a native C++ application can do. C even supports pointers and the concept of unsafe code for those cases in which direct memory access is absolutely critical. The C build process is simple pared to C and C++ and more flexible than in Java. 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. C programs run on the .NET Framework, an integral ponent of Windows that includes a virtual execution system called the mon language runtime (CLR) and a unified set of class libraries. The CLR is Microsoft39。s types, version, culture, and security requirements. 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 CLR performs just in time (JIT) pilation 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. Code that is executed by the CLR is sometimes referred to as managed code, in contrast to unmanaged code which is piled into native machine language that targets a specific system. The following diagram illustrates the piletime and run time relationships of C source code files, the base class libraries, assemblies, and the CLR. 20 Language interoperability is a key feature of the .NET Framework. Because the IL code produced by the C piler 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 CTSpliant 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 in the same language. In addition to the run time services, the .NET Fra