ASP.NET入门C#版英文文献及翻译 第2页
In fact, ASP.NET 1.0 was enthusiastically put to work in dozens of large-scale commercial websites even when it was only in late beta. Despite having similar underpinnings, ASP and ASP.NET are radically different. ASP is a script-based programming language that requires a thorough understanding of HTML and a good deal of painful coding. ASP.NET, on the other hand, is an object-oriented programming model that lets you put together a web page as easily as you would build a Windows application. In many respects, it’s easier to learn ASP.NET than to master ASP, even though ASP.NET is far more powerful. At the same time that server-side web development was moving through an alphabet soup of technologies, a new type of programming was gaining popularity. Developers began to experiment with the different ways they could enhance web pages by embedding multimedia and miniature applets built with JavaScript, DHTML (Dynamic HTML), and Java code. These client-side technologies don’t involve any server processing. Instead, the complete application is downloaded to the client browser, which executes it locally. The greatest problem with client-side technologies is that they aren’t supported equally by all browsers and operating systems.原文请找腾讯752018766辣-文~论.文.网
http://www.751com.cnOne of the reasons that web development is so popular in the first place is because web applications don’t require setup CDs, down-loads, and other tedious (and error-prone) deployment steps. Instead, a web application can be used on any computer that has Internet access. But when developers use client-side technologies, they encounter a few familiar headaches. Suddenly, cross-browser compatibility becomes a problem. Developers are forced to test their websites with differ-ent operating systems and browsers, and they might even need to distribute browser updates to their clients. In other words, the client-side model sacrifices some of the most important benefits of web development or that reason, ASP.NET is designed as a server-side technology. All ASP.NET code executes on the server. When the code is finished executing, the user receives an ordinary HTML page, which can be viewed in any browser. Figure 1-3 shows the difference between the server-side and client-side model. These are some other reasons for avoiding client-side programming: Isolation: Client-side code can’t access server-side resources. For example, a client-side application has no easy way to read a file or interact with a database on the server (at least not without running into problems with security and browser compatibility).security: End users can view client-side code. And once malicious users understand how an application works, they can often tamper with it. one cases, ASP.NET allows you to combine the best of client-side programming with server-side programming. For example, the best ASP.NET controls can intelligently detect the features of the client browser. If the browser supports JavaScript, these controls will return a web page that incorporates JavaScript for a richer, more responsive user interface. However, no matter what the capabilities of the browser, your code is always executed on the server. State limitations: To ensure optimum performance, the Web is built on stateless protocols, which means as soon as a page is sent to a user, the connection is closed and any user-specific information is discarded. ASP includes a session state feature that allows programmers to work around this problem. Using session state, a web application can retain temporary information about each client in server memory. However, session state is useless in scenarios where a website is hosted by several separate web servers. In this scenario, a client might access server B while its session information is trapped on server A and essentially abandoned. ASP.NET corrects this problem by allowing state to be stored in a central repository, such as a separate process or a database that all servers can access.ASP.NET deals with these problems (and many more) by introducing a completely new model for web pages. This model is based on a remarkable piece of technology called the NET Framework. You should understand that the .NET Framework is really a cluster of several technologies: The .NET languages: These include C# and VB .NET (Visual Basic .NET), the object-oriented and modernized successor to Visual Basic 6.0; these languages also include JScript .NET (a server-side version of JavaScript), J# (a Java clone), and C++ with Managed Extensions. he CLR (Common Language Runtime): The CLR is the engine that executes all .NET programs and provides automatic services for these applications, such as security checking, memory management, and optimization. The .NET Framework class library: The class library collects thousands of pieces of prebuilt functionality that you can “snap in” to your applications. These features are sometimes organized into technology sets, such as ADO.NET (the technology for creating database applications) and Windows Forms (the technology for creating desktop user interfaces).ASP.NET: This is the engine that hosts web applications and web services, with almost any feature from the .NET class library.
ASP.NET also includes a set of web-specific services. sual Studio: This optional development tool contains a rich set of productivity and debugging features. The Visual Studio setup CDs (or DVD) include the complete .NET Framework, so you won’t need to download it separately. Interestingly, C# and VB .NET are actually far 上一页 [1] [2] [3] 下一页
ASP.NET入门C#版英文文献及翻译 第2页下载如图片无法显示或论文不完整，请联系qq752018766
