Working with Projects and Solutions
Each time you want to develop an application, you create a project. A project is a collection of files, such as code files, resources, data, and all the other files you need to build your final assembly. A Visual Basic project is represented by a .vbproj file, which is an Extensible Markup Language (XML) file that contains all the information required by Visual Studio to manage files that constitute your project.
Projects are organized into solutions. A solution is basically a container for projects. In fact, solutions can contain infinite projects of different kinds, such as Visual Basic projects, projects produced with programming languages other than Visual Basic, class libraries, projects for Windows client applications, Windows Communication Foundation services, and so on. In other words, a solution can include each kind of project you can create with Visual Studio 2015. Solutions also can contain external files, such as documents or help files. A solution is an .sln file that has an XML structure and stores the information required to manage all the projects contained in the solution. Visual Studio 2015 can also open solutions created with previous versions of the IDE.
Project Upgrades and “Round-Tripping”
You can upgrade previous versions of your solutions by simply opening them in Visual Studio 2015. The new version of the IDE supports project round-tripping, which means you can use Visual Studio 2015 to open a solution created with Visual Studio 2013, Visual Studio 2012, or Visual Studio 2010 with Service Pack 1, with no upgrades; then you can open the same solution back in the Visual Studio version you created the project with. For solutions created with other versions, the Upgrade Wizard can guide you through the upgrade process in a few steps. There are some exceptions to project round-tripping, which you can read about at http://msdn.microsoft.com/en-us/library/hh266747(v=vs.120).aspx.
Typically you manage your projects and solutions by using the Solution Explorer window, which is discussed later in this chapter.