Creating a Simple Test Web API in C#

Introduction

In this blog post, we will create a simple Web API using C# and ASP.NET Core that supports basic CRUD operations such as GET, POST, and DELETE. This API will return test data, making it ideal for learning and testing API development.

Prerequisites

• Install .NET SDK
• Visual Studio or Visual Studio Code
• Basic knowledge of C# and ASP.NET Core

Step 1: Create a New ASP.NET Core Web API Project

Open a terminal or command prompt and run the following command:

 dotnet new webapi -n TestApi        

Navigate to the project directory:

 cd TestApi        

Step 2: Create a Test Model

In the Models folder, create a new class named TestData.cs:

namespace TestApi.Models
{
    public class TestData
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
}        

Step 3: Create a Controller

In the Controllers folder, create a new controller named TestController.cs:

using Microsoft.AspNetCore.Mvc;
using System.Collections.Generic;

namespace TestApi.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class TestController : ControllerBase
    {
        private static List<TestData> _testData = new List<TestData>
        {
            new TestData { Id = 1, Name = "Item 1" },
            new TestData { Id = 2, Name = "Item 2" }
        };

        [HttpGet]
        public IActionResult Get()
        {
            return Ok(_testData);
        }

        [HttpPost]
        public IActionResult Post([FromBody] TestData data)
        {
            _testData.Add(data);
            return CreatedAtAction(nameof(Get), new { id = data.Id }, data);
        }

        [HttpDelete("{id}")]
        public IActionResult Delete(int id)
        {
            var item = _testData.Find(x => x.Id == id);
            if (item == null) return NotFound();
            _testData.Remove(item);
            return NoContent();
        }
    }
}        

Step 4: Run the API

Run the following command to start the API:

 dotnet run        

The API will be available at https://localhost:5001/api/test.

Step 5: Test the API

Use Postman or any API testing tool to test the endpoints:

• GET: https://localhost:5001/api/test
• POST: Send a JSON object { "id": 3, "name": "Item 3" }
• DELETE: https://localhost:5001/api/test/1

Conclusion

This simple Web API in C# demonstrates basic CRUD operations with test data. You can extend it further to connect with a database or add authentication as needed. Happy coding!