Shulou(Shulou.com)06/02 Report--

This article is to share with you how to analyze ASP.NET application web.config files, the editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

ASP.NET is not a simple upgrade of asp, but Microsoft. An important part of the Net program, it relies on. The multi-language and powerful class library support of Net introduces the server-side HTML control and WEB control, automatically handles the interaction between the client side of the control and the server side, provides developers with a window programming interface similar to that under Windows, provides a good programming interface for the development of large-scale network application functions, and can greatly improve the work efficiency of developers.

However, the "convert once, compile twice" process makes aspx files appear slightly inadequate when executed (or run after update), especially in application environments with a large number of aspx and codebehind code files, compiling aspx files to DLL (in. In Net, it is called application set) and then released, saving the time of "one conversion, one compilation" and CPU occupancy rate, which will greatly improve the overall performance of WEB services. Of course, after compiling to DLL, the confidentiality of the source code has also been improved to a certain extent.

Through the analysis of the basic processing flow of ASP.NET and a secret discovered by accident, this paper introduces how to establish the mapping from aspx to DLL in ASP.NET, how to develop a DLL that can handle HTTP request / response, and how to set "trap". The process of compiling a ready-made single aspx file and codebehind's aspx file into DLL, the article *, and also introduces a little skill in the actual operation process.

Since ASP.NET applications, web.config files, etc., are involved, in order to enable readers to better understand the content and not to look cumbersome, let's first introduce the corresponding system environment:

System environment: Win2000 (SP3) + IIS5 + .net Framework 1.0 (Chinese version).

Server name: since the examples in this article are all tested on this machine, the server name is localhost.

IIS setting: create the virtual directory dlltest (the real path is w:\ wwwroot\ dlltest), set it as the application, and create the bin directory under dlltest. All source files will be placed in the dlltest directory, and all dll files will be placed in the dlltest\ bin directory.

ASP.NET application configuration file-web.config creates a web.config file in the dlltest directory with the following initial contents:

Command window (DOS window)

Open a command window and use the cd command to make the current directory w:\ wwwroot\ dlltest.

Establish a mapping from aspx to dll

First, let's look at how aspx files are processed by ASP.NET in general:

When a HTTP request (such as "http://webserver/webapp/webpage.aspx") is sent from the client to the IIS server, the IIS captures and parses the request

◆ when it parses that the request is an aspx page, it immediately calls the ASP.NET runtime environment (aspnet_wp.exe) with "/ webapp/webpage.aspx" as the parameter.

After the ◆ ASP.NET environment starts, check if "/ webapp/webpage.aspx" exists, and if not, return a HTTP 404 (File not found) error to the client

◆ otherwise look for the corresponding dll file in the temporary directory of ASP.NET. If it does not exist or the dll is "older" than the aspx source file, call the csc compiler (if the server scripting language of aspx is VB or JScript, then call the corresponding vbc compiler, jsc compiler) to compile the aspx file into dll

◆ and then ASP.NET calls the dll to process the specific customer request and return the server response.

From this process, we can see that, in general, the ASP.NET runtime environment will automatically identify, check, and update the dll corresponding to aspx. Is there any other way to force the processing of an aspx file to be "routed" to a compiled existing DLL? The way to do this is to add the aspx-to-dll mapping entry in the httpHandlers section of the system.web section of the ASP.NET application configuration file web.config, with the following syntax:

Aspx file: a virtual name that needs to be "routed". The extension must be aspx, otherwise IIS will process the file before the ASP.NET runtime environment.

Dll file: the name of the dll file (application assembly) without entering ".dll" .ASP.NET first searches for assembly DLL in the application's private\ bin directory, and then searches for assembly DLL in the system assembly cache.

Class name: since a dll may have multiple namespaces or classes, you must indicate which class is loaded automatically when dll is called.

For example, the web.config file for an ASP.NET application is as follows:

The configuration file tells ASP.NET that when the client requests the application's index.aspx file, it directly calls the bbs.dll in the application's bin directory and automatically loads the BBS.IndexPage class in it.

The above is how to analyze the web.config files of ASP.NET applications. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.