Migrating from .NET Web Forms to Blazor: A Step-by-Step Guide - Routing

Web technologies change rapidly, and developers need to stay current. One such trend is the move from .NET Web Forms to Blazor - a modern web framework that lets developers build interactive applications with C# and .NET.


Steven Lieberman

1/15/20243 min read


In web development, technologies evolve rapidly, and developers must stay current with the latest trends. One such trend is the migration from .NET Web Forms to Blazor. Blazor is a modern web framework that allows developers to build interactive web applications using C# and . NET.

This step-by-step guide will focus on migrating the routing functionality from .NET Web Forms to Blazor. Routing in Blazor is component-based, unlike the page-based routing in Web Forms. Therefore, it's crucial to understand the differences and adapt your routing strategy accordingly.

Understanding Routing in Blazor

Before diving into the migration process, let's take a moment to understand how routing works in Blazor. In Blazor, routing is based on components. Each component represents a specific page or a section of a page. The corresponding element is rendered when a user navigates to a particular URL.

Blazor uses a combination of route templates and route parameters to define the routing rules. Route templates match URLs, and route parameters allow the passing of dynamic values to components.

Unlike Web Forms, where routing is based on physical files and folders, Blazor's routing is entirely based on the component structure. This component-based approach provides more flexibility and control over the application's navigation flow.

Migrating Web Forms Routing to Blazor

Now that we have a basic understanding of routing in Blazor let's discuss the steps involved in migrating Web Forms routing to Blazor:

Step 1: Analyze and Plan

Start by analyzing the routing structure of your existing Web Forms application. Identify the different pages and their corresponding URLs. Note down any route parameters or query strings used in the URLs.

Once you clearly understand your Web Forms routing, plan the new routing structure in Blazor. Determine which components will replace the existing pages and how the URLs will map to these components.

Step 2: Create Blazor Components

In this step, you must create the necessary Blazor components to replace your Web Forms pages. Each component should represent a specific page or a section of a page.

For example, if you have a Web Forms page called "Products. aspx," you can create a corresponding Blazor component called "Products.razor." Inside this component, you can define the UI and functionality in the original Web Forms page.

Step 3: Define Route Templates

In Blazor, route templates match URLs and determine which component to render. Define route templates for each Blazor component based on the desired URL structure.

For example, if you want the "Products" component to be rendered when the user navigates to "/products" in the browser, you can define the route template as "@page "/products" inside the "Products—razor" component.

Step 4: Handle Route Parameters

If your Web Forms application uses route parameters or query strings, you must handle them in Blazor. Blazor provides built-in mechanisms to control route parameters.

In Blazor, you can define route parameters by adding placeholders in the route template. For example, if your Web Forms URL is "/products/{id}," you can define the route template in Blazor as "@page "/products/{id}.""

To access the route parameter in the corresponding Blazor component, you can use the "@parameter" directive. For example, if you want to access the "id" parameter in the "Products. razor" component, you can use "@parameter int id."

Step 5: Implement Navigation

Now that you have defined the routing structure in Blazor, it's time to implement the navigation logic. Blazor provides several ways to navigate between components.

You can use the built-in NavLink component to create navigation links. The NavLink component automatically adds the necessary CSS classes to indicate the active route.

You can also use the NavigationManager service to navigate to a specific URL programmatically. The NavigationManager provides methods like NavigateTo and NavigateToRelative to handle navigation.


Migration from .NET Web Forms to Blazor is a significant step towards modernizing your web application. Routing is essential to any web application, and understanding the differences between Web Forms and Blazor routing is crucial for a successful migration.

In this guide, we discussed the component-based routing in Blazor and provided a step-by-step approach to migrate Web Forms routing to Blazor. By following these steps, you'll be able to adapt your existing routing structure to the component-based routing in Blazor and take full advantage of its modern web development capabilities.

Remember, the migration process may require additional adjustments based on your specific application's requirements. It's always recommended to thoroughly test the migrated application and ensure all functionality works as expected.