Routing

Goal

This snapshot advances Northline Press by teaching you to organize endpoints with MapGet routes.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use .NET 8 SDK, a terminal, and Docker for Postgres stages. You should recognize C#, HTTP verbs, and basic HTML.

Port 5080 must be free. Copy .env.example and review appsettings.json before database stages.

• .NET 8 SDK
• A code editor and terminal
• Docker from part 4 onward

Concepts

Minimal hosting maps paths to delegates. Route order and HTTP methods both matter.

Keep page models thin: Razor Pages accept input, services and EF Core enforce rules, and Razor escapes output by default.

Walkthrough

Add home, about, and health endpoints on the web application.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

app.MapGet("/about", () => "About Northline Press");

Run and verify

Enter 02-Routing, restore packages, and run on port 5080.

Open http://127.0.0.1:5080. Watch the terminal for validation and database errors.

git clone https://github.com/michaeldunga1/fcc-aspnet-blog.git
cd fcc-aspnet-blog/02-Routing
cp .env.example .env
dotnet restore
dotnet run --urls http://127.0.0.1:5080

Troubleshooting

A missing MapGet call leaves routes undefined. Check both path and HTTP method.

Restore errors usually mean the SDK is missing or you opened the wrong folder. For Postgres failures, confirm Docker is running and the northline_NN database name matches the snapshot.

• Read the first error first
• Restart after environment changes
• Never commit .env or production secrets

Try this

Add a /contact plain-text route.

Test a happy path and one invalid or unauthorized request.

• Make one small change
• Test it in the browser
• Compare with the next snapshot only after it works