11.1 Using NuGet Packages

Let’s go through using NuGet packages in C# — the standard way to add external libraries and dependencies to your project.

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📌 1. What is NuGet?

• NuGet is the package manager for .NET.

• It allows you to install, update, and manage external libraries in your projects.

• Packages can include DLLs, tools, scripts, or content files.

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📌 2. Finding and Installing Packages

Using Visual Studio

1. Right-click on your project → Manage NuGet Packages

2. Browse for the desired package (e.g., Newtonsoft.Json)

3. Click Install → NuGet automatically adds it to your project

Using .NET CLI

dotnet add package Newtonsoft.Json

• Installs the package and updates your project file automatically

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📌 3. Using Installed Packages

After installing, import the namespace in your code:

using Newtonsoft.Json;
 
var person = new { Name = "Alice", Age = 25 };
string json = JsonConvert.SerializeObject(person);
Console.WriteLine(json);

• The package is now ready to use in your project

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📌 4. Updating Packages

Visual Studio

• Go to Manage NuGet Packages → Updates

• Select package → Update

.NET CLI

dotnet add package Newtonsoft.Json --version 14.0.1
dotnet restore

• Ensures you’re using the latest or specific version

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📌 5. Removing Packages

Visual Studio

• Manage NuGet Packages → Installed → Uninstall

.NET CLI

dotnet remove package Newtonsoft.Json

• Cleans up your project dependencies

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📌 6. NuGet Package Configuration

• Packages are tracked in your .csproj file:

<ItemGroup>
  <PackageReference Include="Newtonsoft.Json" Version="14.0.1" />
</ItemGroup>

• Ensures reproducible builds across machines

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📌 7. Best Practices

1. Always use specific versions for production projects

2. Keep dependencies minimal to reduce bloat

3. Regularly update packages to benefit from fixes and features

4. Restore packages on a new machine using:

dotnet restore

• Ensures all dependencies are downloaded

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📌 8. Summary Table

Feature	Description
NuGet	Package manager for .NET
Install package	dotnet add package <PackageName>
Update package	dotnet add package <PackageName> --version x.x.x
Remove package	dotnet remove package <PackageName>
Project reference	<PackageReference> in .csproj
Usage	Import namespace with using

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✅ Tip:

• Think of NuGet as npm for C# — it simplifies adding libraries without manually downloading DLLs.

• Always check license compatibility when adding external packages.