Migrating from ASP.NET to ASP.NET Core involves several steps and potential challenges. First, analyze the existing application’s architecture, dependencies, and compatibility with .NET Core. Use tools like API Portability Analyzer and .NET Upgrade Assistant for assistance.
Next, create a new ASP.NET Core project and incrementally move functionality from the old application. Start by setting up the project structure, middleware pipeline, and configuration settings. Then, migrate data access layer, business logic, and user interface components.
Challenges include:
1. Incompatibility of some libraries or APIs: Replace them with compatible alternatives or use .NET Standard.
2. Changes in authentication and authorization mechanisms: Adapt to ASP.NET Core Identity or other security providers.
3. Differences in configuration management: Transition from web.config to appsettings.json and IConfiguration.
4. Middleware pipeline changes: Reconfigure custom middleware and adapt to built-in middleware differences.
5. Project file format change: csproj files are simplified in .NET Core; manually update or use upgrade tooling.
6. Hosting model updates: Choose between Kestrel or IIS integration, considering performance and feature requirements.
