. NET Development Platform Research (III.)

Visual C + +, the existing programming language for writing low-level code and Windows programs, will continue to exist, but it will be modified to support. NET development platform.

In particular, Visual C + + will get new keywords and data types, called managed Extensions to Visual C + +, which enable programmers to create controllable code. However, these extensions are optional; the Visual C + + version of the. NET Framework is fully backward compatible with its predecessor: Visual c++6.0, which developers can use to write uncontrollable code.

This enables C + + to have a unique location in the. NET domain. All the other Microsoft languages need to be. NET development platform--for example, you cannot use vb.net to create a VB-style component that runs on the old VB runtime, nor can you directly compile a C # application into native Intel directives. However, Visual C + + still has a native compiler. Combining the ability of the CLR to connect new controllable code to existing uncontrolled code means that C + + developers can continue to use exactly the same language and environment as they used to.

Even with managed Extensions, using Visual C + + to write controllable code is still difficult and error prone, because. NET development platform data types and C + +, which means that developers first use Visual C + +, as now used, to write such as low-level device drivers such as uncontrolled code, and then use the managed Extensions to enable the code to collaborate with, or merge with, some of the controllable code from some other source.



JScript.NET

JScript.NET is an updated version of Microsoft's JavaScript (or ECMA script) scripting language, which is different from Java and Visual J # (see below). Compared with VB.net's breakthrough in VB, JScript.NET has a relatively small breakthrough in the current JScript language, typically used for client browser scripting, because JScript already supports similar data types and characteristics as provided by the CLR. However, JScript.NET is not entirely back-compatible, and Microsoft has yet to announce any plans to support the porting of source code to newer languages.

JScript is appealing to web developers who now use JScript and want to leverage their existing knowledge to play the advantages of the CLR and the class library.



Visual C #

With the difficulty of creating controllable code using Visual C + +, Microsoft has created a similar language, called Visual C #, designed to write controllable code.

C # is Microsoft's only language designed specifically for the CLR from the outset, and Microsoft itself has used C # to create controllable code in subsystems such as class libraries and asp.net. In fact, while supporting multiple languages is the primary design goal of the CLR, it may be useful to assume that C # and the CLR are effectively designed together, and that each design affects the other. Does this mean that all programmers should use C #? Of course not.

Although C # is simpler than C + +, it is still deeply rooted in the "C" language family. This means that it inherits features that are not in a language such as VB. For example, the C # language is case sensitive, while VB is not case sensitive. C # requires the developer to explicitly transform the data type, while VB makes some default conversions. C # includes the ability to access the bottom level more directly. NET development platform infrastructure, for example, C # developers can use pointer type directives to access buffered memory and examine the buffer.

Microsoft wisely decided not to use these capabilities in vb.net, because doing so would complicate the VB language, but would only be useful for less advanced VB programmers.

In short, C # attracts programmers who are now working with Visual C + + or Java, and C # is attractive to advanced VB programmers who develop components, and they need a language that is easy to learn using the CLR and class libraries.



Visual j#.net

This is a new language that gives programmers the means to migrate from an existing Visual J + + Java environment to a new. NET development environment.

Visual J #. NET is an external attachment to Visual studio that enables programmers to write applications in Java syntax, but the final application uses the. NET Framework class libraries and the CLR instead of the Sun's Java 2 APIs and Java Visual Machine (JVM) (Java Virtual machine). Visual J #. NET also provides tools for importing and converting J + + applications, programs that can then run under the CLR, and access to the J + + library (for example, Windows Foundation Classes (Windows basic Class Library) through the CLR and COM interoperability features. Visual J #. NET does not use any Sun Java technology, so it is not easy to migrate applications to Sun-compatible java.



For those who have worked with Visual J + + and are familiar with Java syntax, but do not want to convert to. NET development platform for programmers, Visual J #. NET is very attractive.

Visual J #. NET is a stand-alone development plan outside of Visual Studio.NET, and the latest version is a beta version that is not yet available with visual Studio. NET is compatible with the final version.



Visual Studio. NET

In February 2002, Microsoft released the final version of Visual Studio.NET (Vs.net), a set of software development tools that Microsoft strongly recommended for creating. NET applications. Vs. NET for the first time, developers understand the language of Microsoft's revolutionary changes, but also solve many problems in the past, developers use Microsoft tools to create applications.

As Visual Studio.NET improves on debugging and it integrates the tools needed by developers tightly into a single environment, vs.net will greatly impact the development of Web applications.

Previously, developers could embed VB script or JScript only on Web pages. Web pages can now be built in any one of the vs.net languages. The IDE also provides a drag-and-drop GUI that creates Web pages from Web Form controls that are completely dynamic, easy to encode, automate state issues, generate pure HTML based on browser compatibility, and separate user interface issues from coding problems.

Simply drag an external Web services onto the design page, and you can connect it to the project. Creating a Web services simply adds tag attributes to your code. You can use the enhanced HTML and Script Editor. For many web creators, this is a paradise for one side.

In addition, visual Studio.NET also provides fully integrated data processing, particularly XML and database integration, which greatly simplifies the processing of federated data from different types of data sources, such as merging employee data from an Oracle database into an xml-based sales score list.

Previously, code that supported certain controls was hidden, and it was difficult for developers to discover and modify them. Now, all the controls emit code, including formatting code, that can be displayed so that the advanced developer modifies the default behavior of forms and controls, and gives them more compact control over the appearance of the application. (to keep most of the VB user experience, the Vs.net IDE uses outlining to hide the code until the developer wants to browse it.) ）







Choose. NET language rule of thumb

• What are the skills of current programmers and how easy is it to hire new programmers?

• Are the components being developed for a single end-user application, or are the underlying components reused by other programmers in different situations?

• Does the application need to write new code from scratch, or is it possible to simply modify and overwrite existing code?

• Can I use a third party (non-windows) language and tools?

The following rules of thumb can help developers choose. NET Development platform Language:

• Most VB programs are continuing to use VB (VB). NET) will probably benefit a lot.

• For those who are already familiar with the more advanced functions of VB Developers, need to pay attention to C #, as another tool.

• Developers who are already familiar with Java or J + + will find that C # is the best technique for them.

• Overwriting existing native code as. NET code for C + + developers should use managed Extensions to C + +. C + + developers who continue to develop native applications should continue to use the existing C + + language.

• c + + developers who are developing new applications and code basics need to make choices in C # and managed Extensions to C + +. In most cases, these developers will find that the benefits of using C # are very much in line with the learning curve.

• Be interested in scripting Web pages and use JScript to do this, turn to JScript.NET.

• Developers who have used J + + and who prefer Java syntax should consider J #.