How to Get Started with ASP.NET for API Development

ASP.NET is a platform for development internet APIs with C# and .NET. It’s frequently used for app backends, and will mechanically serialize categories to JSON. We’ll stroll via putting in a provider that talks to a database and retail outlets an inventory of items.

Making a Challenge

We’ll be the usage of Visible Studio, because it supplies nice .NET enhance out of the field. Create a brand new challenge the usage of the “ASP.NET Core Internet Utility” template:

create new project

Give it a reputation, and choose “API,” as we’re now not development a ASP.NET frontend right here.

select API

This will likely initialize your resolution with the entire boilerplate had to get a fundamental API up and operating. In case you click on the run button (labelled IIS Categorical, which begins an IIS internet server), you’ll see the API exhibiting some dummy knowledge concerning the climate.

start program

dummy data

We’ll use this base to arrange a easy API that can connect with a database and skim and write customized items. On this case, it’s a number of person knowledge, however the API will in large part paintings the similar for extra sophisticated entity fashions.

Connecting a Database

It’s a good suggestion to separate up the common sense of dealing with requests and the common sense of dealing with speaking to the database. We’ll create a database provider with some purposes for studying and writing, then an a API controller that can reply to requests via speaking to the database provider. The very first thing to do, despite the fact that, is get ASP.NET speaking to a database within the first position.

We’ll wish to set up some applications for operating with a database. Click on on Gear > NuGet Bundle Supervisor, and choose “Set up NuGet Applications For Resolution.”

install nugest packages

In case you’re the usage of a SQL database, the database connection is treated with explicit plugin applications that put in force EntityFrameworkCore for the underlying database. It is a framework that maps C# items to a relational database, and lets you use LINQ queries and different local gear to have interaction with it. You’ll be able to discover a complete record of database suppliers right here for hottest relational databases.

We’ll be going with MongoDB right here, as a result of NoSQL record databases translate to a Listing<Object> beautiful seamlessly, and the MongoDB motive force helps LINQ queries similar to EF Core.

Set up the MongoDB.Driving force bundle:

Installing the MongoDB.Driver package

Create a brand new folder on the root of your challenge known as “Fashions.” In it, create an entity type known as Person.cs, which would be the schema for the gathering that will get saved within the database. You’ll be able to use the [BsonId] and [BsonRepresentation(BsonType.ObjectId)] attributes to inform the MongoDB motive force that this ID string will have to be interpreted as the gathering ID, and can also be handed as kind string even if Mongo internally needs kind ObjectId.

the usage of MongoDB.Bson;
the usage of MongoDB.Bson.Serialization.Attributes;
the usage of Device;

namespace ExampleService.Fashions

    public magnificence Person
        public string Identity  get; set; 
        public string Identify  get; set; 
        public string E-mail  get; set; 
        // and many others...

On this identical folder, create a report known as DatabaseSettings.cs, which can retailer a category and interface for the database settings.

namespace ExampleService.Fashions

We will populate those belongings values in appsettings.json, via including the next configuration:

    "ExampleCollectionName": "Customers",
    "ConnectionString": "mongodb://localhost:27017",
    "DatabaseName": "Instance"

You’ll, in fact, wish to create or rename the Instance database, in addition to create the Customers assortment in it.

In the end, we will be able to upload some code in Startup.cs within the ConfigureServices approach, which can fetch the settings from the appsettings.json report, and check in the interface via Dependency Injection:

public void ConfigureServices(IServiceCollection products and services)

It is important to upload a directive on the best the usage of your Fashions namespace.

Writing a CRUD Database Provider

As soon as the database is hooked up, you’ll be able to upload the provider that can do the speaking. The next magnificence comprises an IMongoCollection that represents the MongoDB assortment in a layout with which C# can simply have interaction. Reads, writes, updates and deletes will at once have an effect on the underlying assortment.

The constructor approach takes the database settings, begins up a brand new shopper, fetches the database, then initializes the _users assortment.

the usage of ExampleService.Fashions;
the usage of MongoDB.Driving force;
the usage of Device.Collections.Generic;
the usage of Device.Linq;

namespace ExampleService.Products and services

    public magnificence ExampleService

The remainder of the category is just a collection of CRUD operations for interacting with the database. Be at liberty to put in force any customized common sense right here.

Again in Startup.cs, you’ll wish to upload this as a provider on startup:

public void ConfigureServices(IServiceCollection products and services)

You’ll once more want every other the usage of directive, this time for ExampleService.Products and services.

Surroundings Up an API Controller

Subsequent, you’ll want a controller to maintain API movements. Happily Visible Studio makes this simple; you’ll be able to right-click on “Controllers” so as to add a brand new controller, with learn/write movements. This will likely create a brand new controller with some fundamental strategies.

Right-click on "Controllers" to add a new controller with read/write actions

The path is outlined on the best. By means of default, that is set to /api/controller, the place controller is the controller title (minus the “Controller” phase). You’ll be able to alternate this should you’d like, however it is a excellent development for most of the people.


You’ll wish to upload a reference in your database provider on the best of the category, and populate it within the constructor:

non-public readonly ExampleService _exampleService;

public ExampleController(ExampleService exampleService)

You’ll wish to alternate the HttpGet approach to go back an ActionResult<Listing<T>> of the schema you’re storing. (It is important to upload a reference in your Fashions namespace, in fact.) ActionResult is a dynamic kind that wraps both the TValue within it, or an HTTP reaction end result.

public ActionResult<Listing<Person>> Get()

    go back _exampleService.Get();

If you wish to upload every other Get approach, however on a special path, you’ll be able to move it as a parameter within the characteristic:

public ActionResult<Listing<Person>> GetSomeThingElse()

Then for the HttpPost approach, name the Create approach of your database provider, and go back CreatedAtRoute, which can ship a 201 reaction to the buyer informing them that the thing advent was once a hit.

public ActionResult<Person> Create(Person userIn)

For the opposite routes, you’ll be able to configure them the way you’d like. The overall thought is to maintain the person enter, carry out any validations you wish to have to, and contact the correct database movements, returning the person a one thing helpful or a standing code telling them what came about.

At this level despite the fact that, you will have to be capable of hit the IIS Categorical run button on the best, and check the API. This will likely default the path to be the elements products and services API that got here with the boilerplate, so relatively than typing it out each time, you’ll be able to alternate the debug path beneath Challenge > Homes > Debug and converting the Release Browser possibility.

change debug route

As soon as you wish to have to check on a far off server, you’ll be able to create a manufacturing construct from Construct > Submit Provider. Make a choice report output, and edit the configuration to fit your wishes. As an example, you’ll be able to make a choice to construct as self-contained, which can bundle the entire .NET dependencies with the construct, and likewise to put up as a unmarried executable. You’ll be able to alternate the objective runtime right here as neatly.

production build settings

If you wish to put up to Linux, you’ll wish to upload a runtime identifier in your .csproj report.


After all, the API featured this is unsecured. ASP.NET has a super authentication gadget, providing enhance for JWT based totally tokens, and can also be configured to paintings with OAuth suppliers like Google and Fb.

Leave a Reply

Your email address will not be published. Required fields are marked *