Solutions and projects in Visual Studio
This article describes the concept of a project and a solution in Visual Studio. It also briefly covers how to create a new project and the Solution Explorer tool window.
This topic applies to Visual Studio on Windows. For Visual Studio for Mac, see Projects and solutions in Visual Studio for Mac.
When you create an app, website, plug-in, etc. in Visual Studio, you start with a project. In a logical sense, a project contains all the source code files, icons, images, data files, etc. that are compiled into an executable, library, or website. A project also contains compiler settings and other configuration files that might be needed by various services or components that your program communicates with.
You don't have to use solutions or projects in Visual Studio to edit, build and debug code. You can simply open the folder that contains your source files in Visual Studio and start editing. For more information, see Develop code in Visual Studio without projects or solutions.
A project is defined in an XML file with an extension such as .vbproj, .csproj, or .vcxproj. This file contains a virtual folder hierarchy, and paths to all the items in the project. It also contains the build settings.
To look at the contents of a project file in Visual Studio, first unload the project by selecting the project name in Solution Explorer and choosing Unload Project from the context or right-click menu. Then, open the context menu again and choose Edit <projectname>.
In Visual Studio, the project file is used by Solution Explorer to display the project contents and settings. When you compile your project, the MSBuild engine consumes the project file to create the executable. You can also customize projects to produce other kinds of output.
A project is contained within a solution. Despite its name, a solution is not an "answer". It's simply a container for one or more related projects, along with build information, Visual Studio window settings, and any miscellaneous files that aren't associated with a particular project. A solution is described by a text file (extension .sln) with its own unique format; it's not intended to be edited by hand.
Visual Studio uses two file types (.sln and .suo) to store settings for solutions:
|.sln||Visual Studio Solution||Organizes projects, project items, and solution items in the solution.|
|.suo||Solution User Options||Stores user-level settings and customizations, such as breakpoints.|
Create new projects
The easiest way to create a new project is to start from a project template for a particular type of application or website. A project template consists of a basic set of pre-generated code files, config files, assets, and settings. These templates are available in the dialog box where you create a new project (File > New > Project). For more information, see Create a new project in Visual Studio and Create solutions and projects.
If you often customize your projects in a certain way, You can create a custom project template that you can then use to create new projects from. For more information, see Create project and item templates.
When you create a new project, it is saved by default at %USERPROFILE%\source\repos. You can change this location in the Projects location setting under Tools > Options > Projects and Solutions > Locations. For more information, see Projects and Solutions page, Options dialog box.
After you create a new project, you can use Solution Explorer to view and manage the project and solution and their associated items. The following illustration shows Solution Explorer with a C# solution that contains two projects:
Many menu commands are available from the right-click menu on various items in Solution Explorer. These commands include building a project, managing NuGet packages, adding a reference, renaming a file, and running tests, just to name a few. The toolbar across the top of Solution Explorer has buttons to switch from a solution view to a folder view, show hidden files, collapse all nodes, and more.
For ASP.NET Core projects, you can customize how files are nested in Solution Explorer. For more information, see Customize file nesting in Solution Explorer.