.Net Core Web API from scratch with Visual Studio Code

Hi all,

In this blog I'll explain you how to build and test .Net Core Web API.
I assume you have installed Visual Studio Code and C# extension which comes to that IDE.
So, Lets get started.

1. Create a folder, I'll name it as CoreWebApi.

2. Open this folder in VS Code.

3. Open its' terminal by pressing Ctrl + ~

4. Create folder called API and go to that folder in terminal.

5. Type 'dotnet new web' and hit Enter.

And you should get the following message:

The template "ASP.NET Core Empty" was created successfully.
This template contains technologies from parties other than Microsoft, see https://aka.ms/template-3pn for details.

6. Go to Startup.cs and add services.AddMvc(); to ConfigureServices(IServiceCollection services) method.
So that method should like as bellow:

public void ConfigureServices(IServiceCollection services)
{
     services.AddMvc();
}

7. Comment app.Run section in Configure method and add app.UseMvcWithDefaultRoute(); to that method.
So that method should like as bellow:

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
      loggerFactory.AddConsole();

      if (env.IsDevelopment())
      {
             app.UseDeveloperExceptionPage();
      }

      // app.Run(async (context) =>
      // {
      //     await context.Response.WriteAsync("Hello World!");
      // });

      app.UseMvcWithDefaultRoute();
}

8. Save and build the project (Ctrl + Shift + B)

9. Resolve problems as bellow:

• Select Yes to the Warn message "Required assets to build and debug are missing from 'TodoApi'. Add them?"
• Select Restore to the Info message "There are unresolved dependencies".

10. Create another folder in API folder called Controllers.

11. Create a C# file inside that folder and name it as UserController.cs

Copy the following code to that file:

using Microsoft.AspNetCore.Mvc;

namespace CoreWebApi.API.Controllers
{
    [Route("api/[controller]")]
    public class UserController : Controller
    {
        [HttpGet]
        [Route("GetUser")]
        public string GetUser()
        {
            return "Prageeth";
        }

        [HttpGet]
        [Route("GetUserWithId")]
        public string GetUserWithId(int id)
        {
            return "Roshane: " + id.ToString();
        }
    } 
}

12. Build and Run the project. 

13. Test the Api End points with your browser or Postman as bellow:

• http://localhost:5000/api/user/GetUser
• http://localhost:5000/api/user/GetUserWithId?id=2

Hope you got the idea to create a .Net Core Web API project from scratch. 

Happy Coding...