What does the .csproj file do?

Updated for .NET 5

This is the most important file in our application. It tells .NET how to build the project.

All .NET projects list their dependencies in the .csproj file. If you have worked with JavaScript before, think of it like a package.json file. The difference is, instead of a JSON, this is an XML file. When you run dotnet restore, it uses this file to figure out which NuGet packages to download and copy to the project folder.

The .csproj file also contains all the information that .NET tooling needs to build the project. It includes the type of the project being built (console, web, desktop, etc.), the platform this project targets and any dependencies on other projects or 3rd party libraries.

Starting in .NET 5, there have been a few major changes to make this file easier to read and maintain, which are listed below.

• In the older versions of .NET, every file in the project had to be listed in the .csproj file. Now they are automatically included and compiled.**
• Previously, GUIDs were used everywhere. Now they are used rarely.
• The path to the DLL files was included, but starting .NET 5, you don't need to specify the path on the disk.

Example:

<!-- Sdk attribute specifies the type of project, which is web. -->
<Project Sdk="Microsoft.NET.Sdk.Web"> 

  <PropertyGroup>
    <!-- TargetFramework is the framework this project will be using, which in this case is .NET 5. -->
    <TargetFramework>net5.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <!-- PackageReference references the NuGet packages. -->
    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />                                              
  </ItemGroup>

</Project>

Note: If you are using Visual Studio, this file will be hidden, but you can right-click on the project and choose edit the project file.