ASP.NET Core 6.0 Features

Last Updated: 5/11/2022

Minimal APIs

  • You can create HTTP APIs with minimal dependencies
  • Ideal for microservices and apps that want to include only minimal files, features and dependencies in ASP.NET Core

Minimal API Code

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/", () => "Hello World");
app.Run();

WebApplication class from Microsoft.AspNetCore is used to configure the pipeline and routes. Use the CreateBuilderstatic method to create a new instance of WebApplicationBuilder

Build the application.

Creates an HTTP GET endpoint / which returns Hello World!

Run the app

Todo CRUD API

In this sample you will create a Todo CRUD API with Entity Framework Core in-memory database provider

Create ASP.NET Core Web API

  • Open Visual Studio 2022
  • Create new project > ASP.NET Core Web API > Next
  • Enter project name TodoApi and click next
  • In framework select .NET 6.0
  • Uncheck use controllers to use minimal API
  • Click Create

Install Nuget Packages

Microsoft.EntityFrameworkCore.InMemory In-memory database provider for Entity Framework Core. Used for testing purposes.

Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore ASP.NET Core middleware for Entity Framework Core error pages. Use this middleware to detect and diagnose errors with Entity Framework Core migrations.

Create Model Todo

namespace TodoApi;

public class Todo
{
    public int Id { get; set; }
    public string? Name { get; set; }
    public bool IsComplete { get; set; }
}

Create TodoDb DbContext

namespace TodoApi;

public class TodoDb: DbContext
{
    public TodoDb(DbContextOptions<TodoDb> options): base(options)
    {

    }

    public DbSet<Todo> Todos => Set<Todo>();
}

Add API Code

using Microsoft.EntityFrameworkCore;
using TodoApi;

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddDbContext<TodoDb>(opt => opt.UseInMemoryDatabase("TodoList"));
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

app.MapGet("/todoitems", async (TodoDb db) => await db.Todos.ToListAsync());

app.MapGet("/todoitems/complete", async(TodoDb db) => await db.Todos.Where(t => t.IsComplete).ToListAsync());

app.MapGet("/todoitems/{id}", async (int id, TodoDb db) => await db.Todos.FindAsync(id) is Todo todo ? Results.Ok(todo) : Results.NotFound());

app.MapPost("/todoitems", async (Todo todo, TodoDb db) => 
{
    db.Todos.Add(todo);
    await db.SaveChangesAsync();

    return Results.Created($"/todoitems/{todo.Id}", todo);
});

app.MapPut("/todoitems/{id}", async (int id, Todo inputTodo, TodoDb db) =>
{
    var todo = await db.Todos.FindAsync(id);
    if (todo is null) return Results.NotFound();
    todo.Name = inputTodo.Name;
    todo.IsComplete = inputTodo.IsComplete;
    await db.SaveChangesAsync();
    return Results.NoContent();
});

app.MapDelete("/todoitems/{id}", async (int id, TodoDb db) =>
{
    if (await db.Todos.FindAsync(id) is Todo todo)
    {
        db.Todos.Remove(todo);
        await db.SaveChangesAsync();
        return Results.Ok(todo);
    }
    return Results.NotFound();
    
});

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.Run();

In the previous versions, the host builder in configured in Program.cs and you use ConfigureServices to add the services to the container and Configure to configure the HTTP request pipeline in the Startup.cs

From ASP.NET Core 6.0, all the configurations are done in Program.cs itself. You now use builder.Services.AddXXX method syntax to add services to the container and app.UseXXX() method syntax to configure the pipeline

Run the Application

Run the application. Use the Swagger UI to test the API.

References

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