This is a class module code file written in C#, which handles business logic. It can be opened with Visual Studio. This is Microsoft's comprehensive programming tool. The latest one is Visual Studio2008, which is very large.
You can refer to the following:
.sln: Solution file, which provides the solution explorer with the information required to display the graphical interface of the management file.
.csproj: Project file, information about references, data connections, folders, and files needed to create the application.
.aspx: A Web Forms page consists of two parts: visual elements (HTML, server controls, and static text) and the programming logic of the page. Visual Studio stores these two components in a separate file. Visual elements are created in .aspx files.
.ascx: ASP.NET user controls (also called "pagelets") are used as a way to encapsulate specific functions and behaviors (both of which are to be used on various pages of a Web application) ) Web pages are developed. A user control contains a combination of HTML, code, and other Web or user controls, and is saved in its own file format on the Web server, with the extension *.ascx. The default configuration in ASP.NET does not allow Web clients to access these files through URLs, but other pages of this website can integrate the functions contained in these files.
.aspx.cs: The programming logic of the Web Forms page is located in a separate class file, which is called the code-behind class file (.aspx.cs).
.cs: Class module code file. Code for the business logic processing layer.
.asax: The Global.asax file (also called an ASP.NET application file) is an optional file that contains code that responds to application-level events raised by the ASP.NET or HTTP modules.
.config: Web.config files provide configuration information to the directory in which they reside and all subdirectories.
.aspx.resx/.resx: Resource file, a resource is any non-executable data logically deployed by the application. By storing data in resource files, the data can be changed without recompiling the entire application.
.XSD: A type of XML schema. Developed from DTD and XDR to XSD.
.pdb: PDB (Program Database) file holds debug and project status information, allowing incremental linking of a program's debug configuration.
.suo: Solution User Options, records all options that will be associated with the solution so that every time it is opened, it includes the customizations you have made.
.asmx: The asmx: file contains WebService processing instructions and serves as the addressable entry point for XML Web services.
.vsdisco (project discovery): File An XML-based file that contains links (URLs) to resources that provide discovery information for a web service.
.htc: An HTML file that contains scripts and a series of HTC-specific elements that define components. htc provides a mechanism for implementing components in scripts.