Migrating .NET Framework Application to .NET Core: A Step-by-Step Guide

As the software development landscape evolves, migrating your application from .NET Framework to .NET Core is a strategic move that brings benefits like cross-platform compatibility, performance improvements, and access to the latest features.

In this step-by-step guide, we’ll navigate through the migration process, ensuring a smooth transition for your entire application.

Step 1: Assessing Compatibility

Background

Before diving into the migration, assess your application’s compatibility with .NET Core using tools like the .NET Portability Analyzer. Identify dependencies and third-party libraries that might need updates.

Implementation

Install the .NET Portability Analyzer

dotnet tool install -g dotnet-portability-analyzer

Analyse the .NET Framework Application

dotnet-analyze portability -f net48 -t netcoreapp3.1 -d [YourAssemblyPath]

Step 2: Updating Dependencies and NuGet Packages

Background

Ensure that all dependencies and NuGet packages used in your application are compatible with .NET Core.

Implementation

Update NuGet Packages: Open the Package Manager Console and run

Update-Package

Check Compatibility: Use the .NET CLI to check for compatibility issues

dotnet restore

Step 3: Converting the Project File

Background

.NET Core uses a different project file format (.csproj) than .NET Framework. Convert your existing project file for compatibility.

Implementation

1. Backup Your Project File: Ensure you have a backup of your existing .csproj file.
2. Convert to .NET Core: Use the .NET CLI to convert the project file

dotnet new console

Merge Changes: Merge the changes from the generated .csproj file into your original project file.

Step 4: Configuring Startup and Program Files

Background

.NET Core applications have a different structure for the Startup and Program files. Update these files accordingly.

Implementation

1. Create a New Startup File: Create a new Startup.cs file with the necessary configuration.
2. Update Program File: Update the Program.cs file to use the new Startup file

.UseStartup<Startup>()

Step 5: Handling Configuration Changes

Background

Configuration in .NET Core is typically managed through appsettings.json files. Migrate your configuration settings to the new format.

Implementation

1. Create appsettings.json: Create an appsettings.json file and move configuration settings.
2. Update Configuration Code: Modify code accessing configuration settings to use the new Configuration object.

Step 6: Migrating Entity Framework

Background

If your application uses Entity Framework, ensure a smooth transition to .NET Core’s Entity Framework Core.

Implementation

1. Install EF Core: Install Entity Framework Core NuGet packages:

dotnet add package Microsoft.EntityFrameworkCore

2. Update DbContext: Update your existing DbContext class to inherit from DbContext in EF Core.

Step 7: Testing and Debugging

Background

Thoroughly test your application to identify and address any issues introduced during the migration.

Implementation

1. Run Unit Tests: Execute existing unit tests to ensure functionality remains intact.
2. Debugging: Debug the application, paying attention to any exceptions or unexpected behaviour.

Step 8: Updating Deployment Scripts

Background

Update deployment scripts to accommodate the changes introduced by .NET Core.

Implementation

1. Update Build Scripts: Modify build scripts to use the .NET Core CLI for building the application.
2. Update Deployment Scripts: Adjust deployment scripts to account for changes in file structure and dependencies.

Step 9: Continuous Integration/Continuous Deployment (CI/CD) Pipeline

Background

Implement a CI/CD pipeline to automate the build and deployment processes.

Implementation

1. Choose CI/CD Tool: Select a CI/CD tool compatible with .NET Core, such as Azure DevOps, Jenkins, or GitHub Actions.
2. Configure Pipeline: Set up a pipeline to build, test, and deploy your application automatically.

Conclusion

Congratulations! You’ve successfully migrated your application from .NET Framework to .NET Core. By following this step-by-step guide, you’ve embraced the benefits of a more modern, cross-platform framework, setting the stage for future innovation and efficiency.

As you continue developing and enhancing your application, keep exploring the capabilities of .NET Core and its ecosystem.

Happy coding!