【正文】 使用自己的東西，構(gòu)建一個(gè)成熟的、高性能的引擎體系結(jié)構(gòu)已經(jīng)成為一個(gè)遺囑。除此之外，在容易開發(fā)和性能之間， HTTP 運(yùn)行時(shí)還提供了最佳的靈活性。你可以在處理請(qǐng)求之前或之后過 濾內(nèi)容，或者僅僅把匹配指定簽名的客戶端請(qǐng)求直接路由到你的代碼里或轉(zhuǎn)向其它的 URL。所以，此框架具有非常高的可擴(kuò)展性。通過使用內(nèi)置的管道路由請(qǐng)求， HTTP 運(yùn)行時(shí)提供了一套復(fù)雜的，但卻很優(yōu)雅的機(jī)制。事實(shí)上， HTTP運(yùn)行時(shí)是一個(gè)組件，你可以把它宿主在IIS之外的應(yīng)用程序上。它獲取客戶端請(qǐng)求，然后通過它內(nèi)置的管道，把請(qǐng)求傳到一個(gè)終點(diǎn)，在這個(gè)終點(diǎn)， 開發(fā)者可以添加處理這個(gè)請(qǐng)求的邏輯代碼。它不僅僅只是WebForms 和 WebServices。 1 是什么？ 我們從最簡(jiǎn)單的定義開始， ？我通常喜歡用如下語句來描述 。 摘要 Web程序的強(qiáng)大平臺(tái)，提供了強(qiáng)大的柔性和能力以至于它可以構(gòu)建任意的 Web程序。 1 原文 1 A lowlevel Look at the Architecture Abstract is a powerful platform for building Web applications that provides a tremendous amount of flexibility and power for building just about any kind of Web application. Most people are familiar only with the high level frameworks like WebForms and WebServices which sit at the very top level of the hierarchy. In this article I’ll describe the lower level aspects of and explain how requests move from Web Server to the runtime and then through the Http Pipeline to process requests. What is Let’s start with a simple definition: What is ? I like to define as follows: is a sophisticated engine using Managed Code for front to back processing of Web 39。s much more than just WebForms and Web Services… is a request processing engine. It takes an ining request and passes it through its internal pipeline to an end point where you as a developer can attach code to process that request. This engine is actually pletely separated from HTTP or the Web Server. In fact, the HTTP Runtime is a ponent that you can host in your own applications outside of IIS or any server side application altogether. The runtime provides a plex yet very elegant mechanism for routing requests through this pipeline. There are a number of interrelated objects, most of which are extensible either via subclassing or through event interfaces at almost every level of the process, so the framework is highly extensible. Through this mechanism it’s possible to hook into very low level interfaces such as the caching, authentication and authorization. You can even filter content by pre or post processing requests or simply route ining requests that match a specific signature directly to your code or another URL. There are a lot of different ways to acplish the same thing, but all of the approaches are straightforward to implement, yet provide flexibility in finding the best match for performance and ease of development. The entire engine was pletely built in managed code and all of the extensibility functionality is provided via managed code extensions. This is a testament to the power of the .NET framework in its ability to build sophisticated and very performance oriented architectures. Above all though, the most impressive part of is the thoughtful design that makes the architecture easy to work with, yet provides hooks into just about any part of the request processing. 2 With you can perform tasks that previously were the domain of ISAPI extensions and filters on IIS – with some limitations, but it’s a lot closer than say ASP was. ISAPI is a low level Win32 style API that had a very meager interface and was very difficult to work for sophisticated applications. Since ISAPI is very low level it also is very fast, but fairly unmanageable for application level development. So, ISAPI has been mainly relegated for some time to providing bridge interfaces to other application or platforms. But ISAPI isn’t dead by any means. In fact, on Microsoft platforms interfaces with IIS through an ISAPI extension that hosts .NET and through it the runtime. ISAPI provides the core interface from the Web Server and uses the unmanage