Projects and Solutions

A project is a group of files that produces some specific output. This output may be a compiled executable program, a dynamic-link library (DLL) of classes for use by other projects, or a custom control for use on other Windows forms.

A solution is a group of one or more projects that should be managed together. For example, suppose that you are building a server application that provides access to your order database. You are also building a client program that each of your sales representatives will use to query the server application. Because these two projects are closely related, it might make sense to manage them in a single solution. When you open the solution, you get instant access to all the files in both projects.

Both projects and solutions can include associated files that are useful for building the application but that do not become part of a final compiled product. For example, a project might include the application’s proposal and architecture documents. These are not included in the compiled code, but it is useful to associate them with the project.

When you open the project, Visual Studio lists those documents along with the program files. If you double-click one of these documents, Visual Studio opens the file using an appropriate application. For example, if you double-click a file with a .doc extension, Visual Studio normally opens it with Microsoft Word.

To associate one of these files with a project or solution, right-click the project in the Solution Explorer (more on the Solution Explorer shortly). Select the Add command’s Add New Item entry, and use the resulting dialog box to select the file you want to add.

Often a Visual Basic solution contains a single project. If you just want to build a small executable program, you probably don’t need to include other programming projects in the solution.

Another common scenario is to place Visual Basic code in one project and to place documentation (such as project specifications and progress reports) in another project within the same solution. This keeps the documentation handy whenever you are working on the application but keeps it separate enough that it doesn’t clutter the Visual Studio windows when you want to work with the code.

Although you can add any file to a project or solution, it’s not a good idea to load dozens of unrelated files. Although you may sometimes want to refer to an unrelated file while working on a project, the extra clutter brings additional chances for confusion. It will be less confusing to shrink the Visual Basic IDE to an icon and open the file using an external editor such as Word or WordPad. If you won’t use a file very often with the project, don’t add it to the project.