📦 Assemblies and GAC in .NET Core

📦 Assemblies and GAC in .NET Core

🔧 What is an Assembly?

An Assembly is a compiled code library used for deployment, versioning, and security in .NET applications. It can be a .dll or .exe file and contains metadata, code, and resources.

📘 Example

  // After building a project named MyApp
  // You get MyApp.dll or MyApp.exe in the bin/Debug folder
  

🧩 Types of Assemblies

• Private Assembly: Used only by a single application.
• Shared Assembly: Intended for use by multiple applications (requires strong naming).

🏛️ What is GAC?

The Global Assembly Cache (GAC) is a machine-wide store used in the .NET Framework to hold shared assemblies. It allows multiple applications to share libraries without duplication.

🚫 GAC in .NET Core?

.NET Core does not use GAC. Instead, it relies on:

• NuGet packages: For dependency management.
• Runtime Store: A shared location for precompiled packages (introduced in .NET Core 2.0).
• Framework-dependent deployment (FDD): Apps depend on a shared system-wide .NET Core runtime.

✅ Best Practices

• Use NuGet for managing shared libraries.
• Prefer self-contained deployments for portability.
• Use strong naming only if needed for versioning or security.
• Keep assemblies modular and focused on single responsibilities.

📌 When to Use Assemblies

• To organize code into reusable components.
• To separate concerns across different projects.
• To share functionality across multiple applications.

⚠️ Precautions

• Ensure version compatibility when sharing assemblies.
• Avoid circular dependencies between assemblies.
• Use semantic versioning for NuGet packages.

🎯 Advantages in .NET Core

• Lightweight: No need for GAC simplifies deployment.
• Modular: Apps include only required assemblies.
• Cross-platform: Works seamlessly on Windows, Linux, and macOS.
• Flexible deployment: Choose between framework-dependent or self-contained models.

📝 Conclusion

Assemblies remain the core building blocks of .NET Core applications, but the GAC model has been replaced with more flexible and modern approaches like NuGet and runtime stores. This shift enhances portability, modularity, and cross-platform support.