.CSPROJ

Introduction

A .csproj file is a C# project for Microsoft’s Visual Studio and the .NET SDK. It says what kind of program the project builds, which .NET version it targets, which source files and resources go into it, and which NuGet packages and other projects it uses. The other Visual Studio languages use the same format under their own extensions: .vcxproj for C++, .vbproj for Visual Basic and .fsproj for F#. Several projects are usually gathered in a solution.

All of them are MSBuild files: MSBuild, Microsoft’s build engine, reads the project and carries out the build, both inside Visual Studio and from the command line.

Structure

A project is an XML document with a Project root. Inside, PropertyGroup elements set properties such as OutputType and TargetFramework; ItemGroup elements list items such as Compile source files, PackageReference NuGet packages and ProjectReference links to other projects; Target elements define build steps; and Import pulls in shared .props and .targets files.

Modern .NET projects are “SDK-style”: the root names an SDK, such as Microsoft.NET.Sdk, which supplies the defaults and includes every source file in the folder automatically, so the file stays short. Older .NET Framework projects and C++ .vcxproj files list every file and setting, separately for each configuration and platform, and are much longer.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
  </ItemGroup>
</Project>

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