How do I migrate from ASP.NET webforms to .NET 8?

Hello Lucian,

Migrating to .NET 8 can be a smooth process, and I'm here to guide you through it. You have several options for technology, including Blazor, MVC, and Razor. Here's a quick overview to help you decide:

• Blazor: This is a powerful PWA-based technology that supports both client-side and server-side development with WebAssembly (WASM).
• MVC/Razor: Opt for MVC with Razor or Razor Pages for a more traditional approach.

Remember, the foundation of any web application remains HTML, CSS, and JavaScript. Browsers interpret only these languages, so your existing WebForms, which use server-side controls or HTML, can be leveraged directly. You can use CSS and JavaScript without modification.

Here's a suggested approach:

1. WebForms Transition: Start by executing a simple WebForm page, such as contactus.aspx. Copy the source HTML, CSS, and JavaScript, and paste them into the relevant view file, like inside the HOME controller with a ContactUS Action Method. For example, convert `` to ``. Avoid HTML helpers and focus on using HTML controls and client-side validation.

2.Data Management: Move your CRUD operations to a class library using .NET Standard if feasible. This will future-proof your code. If not, keep them within the controllers.

3.Embrace New Features: To harness the full potential of .NET 8, utilize ASYNC, TASK, IACTIONRESULT, and incorporate dependency injection and caching.

If you find my approach helpful, I can walk you through each step in detail.

Step-by-step migration will help reduce risks and ensure that your application continues to run while you transition to .NET 8.

Phase 1: Analysis and Preparation

• Inventory your WebForms application:
  • Identify which pages and features can be migrated first (low-risk, non-critical parts).
  • Create a migration roadmap: Identify the parts that need immediate migration and the parts that can be moved later.
• Telerik Controls: Check the availability of Telerik controls for Blazor and MVC. Telerik offers components for Blazor that you can use to replace WebForms controls.

Phase 2: Modernize the Database Access Layer

• Since you are using SQL Server, you can likely continue using Entity Framework or migrate to Entity Framework Core.
• Start by modernizing your data access layer (DAL) to work with Entity Framework Core. This will be compatible with both .NET Framework and .NET 8.

Phase 3: Migrate Authentication and Authorization

• Authentication/Authorization: Consider upgrading to ASP.NET Core Identity or a third-party authentication provider that works across both .NET Framework and .NET 8 apps.
  • If your WebForms app uses Forms Authentication, replace it with ASP.NET Core Identity in the new parts.
  • Use shared cookies across both the old and new applications for seamless user experience.

Phase 4: Migrate One Section at a Time

• Move non-critical pages to Blazor or Razor Pages first:
  • Start with less complex pages like reports, user profiles, or admin panels.
  • Create these pages in the new technology (e.g., Blazor or Razor Pages) and integrate them into the existing WebForms application.
  • For example, you could set up a new route like /new-page that points to the new .NET 8 Blazor/Razor Page.

Phase 5: Replace WebForms Controls Gradually

• Begin replacing WebForms controls with Telerik Blazor controls. Telerik provides similar controls for Blazor that you’re already familiar with in WebForms.
• For complex controls like grids, charts, and form elements, use Telerik’s Blazor controls to recreate the functionality in the new application.

Phase 6: Migrate the Core Business Logic

• Migrate your core business logic to .NET Standard libraries or .NET 8. This will allow the logic to be used in both the WebForms and Blazor applications, reducing duplication.
• Services, repositories, and utilities can be moved to a shared .NET Standard or .NET Core class library that both WebForms and Blazor apps can reference.

Phase 7: Migrate Complex Pages and Finish the Migration

• Once you’ve successfully migrated several simple pages and controls, you can start moving the more complex and critical parts of the WebForms app to the new Blazor/Razor Pages/MVC app.
• Gradually phase out WebForms pages and replace them with Blazor or Razor Pages, following your migration roadmap.

Testing and Deployment

• Make sure to thoroughly test each part of the migrated application.
• Use tools like Azure DevOps or Jenkins to automate testing and deployments.

ASP.NET WebForms is not supported in .NET Core and beyond, including .NET 8. This means that you’ll need to replace WebForms with modern web technologies like Blazor, Razor Pages, or ASP.NET Core MVC.

Since you are heavily using Telerik controls, it’s important to check whether Telerik offers support for Blazor or ASP.NET Core MVC controls (which they do).

There are three main options for replacing WebForms:

• Blazor: If you want to retain a component-based development model similar to WebForms, Blazor is an excellent choice. Blazor allows you to create rich, interactive UI using C# instead of JavaScript.
• Razor Pages: This is a page-centric approach that is simpler than MVC but still gives you the power of server-side rendering with a similar feel to WebForms.
• ASP.NET Core MVC: If your WebForms app is more complex and you need a robust, scalable approach, MVC might be a good fit. It’s a bit more complex than Razor Pages but offers greater control over routing and separation of concerns.

Recommendation: Since you are migrating in steps and want to run the old and new parts of the application in parallel, Blazor is a good option because it’s closer to WebForms in terms of UI interaction, and Telerik offers Blazor components. You can also consider Razor Pages if you want something lightweight but familiar.

During migration, you can use the side-by-side approach where you run parts of your application in .NET Framework (WebForms) and others in .NET 8 (Blazor, Razor Pages, or MVC).

• ASP.NET Core and ASP.NET Framework in the Same Application:
  • You can run both .NET Framework and .NET Core (or .NET 8) applications on the same server and share cookies, authentication, and session state. This allows for a phased migration where some parts of your app stay in WebForms, while others move to the newer framework.
  • This requires hosting the old WebForms app in IIS, while the new .NET 8 app (Blazor/MVC) can be hosted either in IIS or as a standalone app.