How to Migrate from .NET Framework to .NET Core Easily

1. Evaluate Compatibility Gaps

To avoid having to figure everything out yourself, you can turn to the .NET Framework to .NET Core Migration Services, but you need to know how it works. So keep reading.

Not all .NET Framework libraries and APIs map one-to-one with .NET Core, at least not yet.

Analyse to reveal compatibility gaps based on the specific .NET Framework version and feature set your current codebase relies on. Identify the use of any discontinued or changed namespaces, methods, and components that will break when ported “as is”.

Highlight Windows-specific dependencies like WPF forms and wrapping DLLs that won’t translate over to .NET Core’s cross-platform nature. Having an inventory of incompatible elements upfront directs the required code rewrites.

2. Containerise Existing Application

Rather than directly tampering with production systems, first, encapsulate your current .NET Framework application and all coupled databases within Docker containers. This isolated environment lets you safely evaluate migration approaches without destabilising business operations. Containerisation also sets the foundation for smooth cloud deployments later.

Use container orchestration platforms like Kubernetes to then scale up copies of containerised applications for parallelised testing, feature development, and eventually phased rewrite rollouts.

3. Install .NET Core SDK 

With a containerised version of your legacy app and data layer up, provision a development machine installed with the latest .NET Core SDK. Set up the exact same databases and supportive software too like message queues and caching servers. 

This separate cloned environment containing a replica of dependencies allows “mix-and-match” testing as pieces get ported incrementally.

4. Start Porting Code Gradually

Rather than a risky wholesale rewrite, use a stratified approach that gradually ports over pieces of .NET Framework code into .NET Core aligned with your compatibility analysis. Many projects section code into logical layers like:

• presentation layer (UI, menus);
• business logic layer (core processing rules);
• data access layer (database communication).

Pick a single layer, say the data layer first, to focus initial .NET Core transition efforts on. This exposes integration issues early while isolating impact. Once ported, ensure thorough testing before moving up to higher layers.

5. Leverage Automated Code Translation Tools 

To accelerate mechanical code conversions, take advantage of automated translation tools provided by Microsoft and third parties. Be aware results do require subsequent manual review and tweaking for precision. Top utilities include:

1. Xamarin Assistant – Simplifies moving Windows desktop applications to .NET Core 3 by generating mobile UI frameworks.
2. SDK Migrator – Auto converts source code from .NET Framework to .NET Core by rewriting namespaces, packages, and API calls.
3. .NET Portability Analyser – Scans assemblies and highlights incompatible APIs on a granular level. It also provides suggestions for alternate namespaces and methods during migrations.

6. Prioritise Testing

With so many moving parts between old and new code forms, rigorously test each piece as ported over to catch errors early. Unit tests individual functions and modules first in isolation. Follow with more expansive integration and user acceptance testing across migrated full stack layers. Confirm high test coverage to help quantify migration progress and completion.

7. Phase Roll Outs

Once confidence is gained through successive validation testing, aim for a gradual staged rollout of the modernised .NET Core application updated various vertical slices of functionality: 

1. Start with non-customer-facing capabilities first like computational processes and administrative features.
2. User interfaces and front-end web MVC layers can translate over next.
3. Transition customer-impacting modules only after full integration testing.

With each rollout phase, divert only a percentage of production traffic to modern infrastructure while monitoring carefully before redirecting more. This reduces rollback efforts if issues emerge. Within a few iterative releases, 100% traffic cuts over completing migration!

Bottom Line

By following structured porting techniques enterprises can confidently transition legacy .NET apps over to cloud-ready .NET Core platforms without introducing risk. The results make applications resilient and ready for modern innovations!