Section 6.1. Visual Studio Application Types

6.1. Visual Studio Application Types

The original version of Visual Basic generated applications that were form-focused and included rich features for interaction with the user and the Windows environment. Later releases added support for DLL generation, specifically ActiveX DLLs. With its integration into .NET, Visual Basic compiler can now generate several specific types of output.

Windows (Forms) Applications

In .NET, Windows applications make heavy use of the System.Windows.Forms namespace and the control classes contained within it. Although these applications may look like any other non-.NET Windows application, internally they are quite different and are fully managed by the .NET Common Language Runtime.

Console Applications

Back in the days before Windows and other GUI-based platforms, most applications were console applications . These wonders of technology interacted with the user through the medium of the 80 x 24 character screen display. Such programs generally displayed text on the screen and then waited for keyboard input from the user before continuing. Some systems were able to make use of simple graphic characters and screen positioning to give some semblance of a graphical user interface, but this was generally done by sending special display codes to the basic text display.

Console applications are often procedural in nature; they start at the beginning of the application and run until the end, uninterrupted by external user events like mouse clicks. In this era of Windows applications, console applications exist to provide some basic textual information to the user or to control some service or process that does not logically have a need for a user interface.

Windows Services

Windows services are long-running applications that interact directly with the system but not with the user. In fact, they run only within the context of the Windows Service architecture; you cannot start them directly like an EXE file. Even when they run, they belong to the system (in terms of their security profile), not the local user.

Class Libraries

Class libraries are more commonly called dynamic link libraries, or DLLs. Although not true standalone applications, most applications would be limited without the plethora of available DLLs; the functionality in the .NET Framework Class Library is made available through DLL files. DLLs are loaded at runtime by the applications that use them, and they run in the program space of the controlling application. A special variation of a class library, the Web Control Library, is used for ASP.NET server controls.