ASP.NET WEB API With Entity Framework 6 Code First Technique - Part 4

Before proceeding to this article, please go through my previous articles:

• ASP.NET WEB API with Entity Framework 6 code first technique- Part I
• ASP.NET WEB API with Entity Framework 6 code first technique- Part 2
• ASP.NET WEB API with Entity Framework 6 code first technique- Part 3

In this article we are going to learn how to call ASP.NET WEB API from .NET Application.

Create One Employee model class in the project

public class Employee
{
    [Key]
    public int EmployeeId
    {
        get;
        set;
    }
    public string FirstName
    {
        get;
        set;
    }
    public string LastName
    {
        get;
        set;
    }
    public int Age
    {
        get;
        set;
    }
}

 

Create a Context class in the project:

public class CRUDAPIContext : DbContext
   {
       public CRUDAPIContext() : base("name=CRUDAPIContext")
       {
       }

       public System.Data.Entity.DbSet<CRUDAPI.Models.Employee> Employees { get; set; }
   }

The Employees Controller class

public class EmployeesController : ApiController
    {
        private CRUDAPIContext db = new CRUDAPIContext();

        // GET: api/Employees
        public IQueryable<Employee> GetEmployees()
        {
            return db.Employees;
        }

        // GET: api/Employees/5
        [ResponseType(typeof(Employee))]
        public async Task<IHttpActionResult> GetEmployee(int id)
        {
            Employee employee = await db.Employees.FindAsync(id);
            if (employee == null)
            {
                return NotFound();
            }

            return Ok(employee);
        }

        // PUT: api/Employees/5
        [ResponseType(typeof(void))]
        public async Task<IHttpActionResult> PutEmployee(int id, Employee employee)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != employee.EmployeeId)
            {
                return BadRequest();
            }

            db.Entry(employee).State = EntityState.Modified;

            try
            {
                await db.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!EmployeeExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.OK);
        }

        // POST: api/Employees
        [ResponseType(typeof(Employee))]
        public async Task<IHttpActionResult> PostEmployee(Employee employee)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.Employees.Add(employee);
            await db.SaveChangesAsync();

            return CreatedAtRoute("DefaultApi", new { id = employee.EmployeeId }, employee);
        }

        // DELETE: api/Employees/5
        [ResponseType(typeof(Employee))]
        public async Task<IHttpActionResult> DeleteEmployee(int id)
        {
            Employee employee = await db.Employees.FindAsync(id);
            if (employee == null)
            {
                return NotFound();
            }

            db.Employees.Remove(employee);
            await db.SaveChangesAsync();

            return Ok(employee);
        }
}
}

SQL Table

  

 

Our API’s are ready, so now we can call these API from the .NET Application. In my case I’m taking a console Application.

Create one console Application:

Installing the WEB API Client libraries:

Use NuGet Package Manager to install the Web API Client Libraries package for Console Application or else use Install –Package Microsoft.AspNet.WebApi.Client command in package manager console. 

 

Create a Model class in Console Application

public class Employee
{
    public int EmployeeId
    {
        get;
        set;
    }
    public string FirstName
    {
        get;
        set;
    }
    public string LastName
    {
        get;
        set;
    }
    public int Age
    {
        get;
        set;
    }
}

Call GetEmployees API Action from Console Application using HTTP Client

HTTP Client:

It is a class which is from System.Net.Http Namespace and provides a base class for sending HTTP requests and receiving HTTP responses from a resource identified by a URI.

Example

class Program
  {
      static void Main(string[] args)
      {
          ApiCall().Wait();
      }
      static async Task ApiCall()
      {
          using (var client = new HttpClient())
          {

              HttpResponseMessage response =  client.GetAsync("http://localhost:57135/api/Employees/1").Result;
              if (response.IsSuccessStatusCode)
              {

                  Employee emp = await response.Content.ReadAsAsync<Employee> ();

                  Console.WriteLine("{0}\t{1}\t{2}\t{3}", emp.EmployeeId, emp.FirstName, emp.LastName, emp.Age);
                  Console.ReadKey();

              }
          }
      }
  }

Result

Call Employees POST API Action

class Program
    {
        static void Main(string[] args)
        {
            ApiCall();
        }
        static void ApiCall()
        {
            using (var client = new HttpClient())
            {
                //HTTP POST

                var addEmp = new Employee() { FirstName = "John", LastName = "Miller", Age = 25 };
                HttpResponseMessage response =  client.PostAsJsonAsync("http://localhost:57135/api/Employees", addEmp).Result;
                Console.WriteLine("{0}\t{1}", "StatusCode:", response.StatusCode);
                Console.ReadKey();


            }
        }
    }

Result

 

 

Reflection in SQL Table

 

Call Employees PUT API Action

class Program
   {
       static void Main(string[] args)
       {
           ApiCall();
       }
       static void ApiCall()
       {
           using (var client = new HttpClient())
           {
               //HTTP PUT

               var updateEmp = new Employee() {EmployeeId=3, FirstName = "John", LastName = "Miller", Age = 27 };

               HttpResponseMessage response =  client.PutAsJsonAsync("http://localhost:57135/api/Employees/3", updateEmp).Result;
               Console.WriteLine("{0}\t{1}", "StatusCode:", response.StatusCode);
               Console.ReadKey();

           }
        }
        }

Result

 

  

 

 Reflection in SQL Table

 

Call Employees Delete API Action

class Program
    {
        static void Main(string[] args)
        {
            ApiCall();
        }
        static void ApiCall()
        {
            using (var client = new HttpClient())
            {
                //HTTP DELETE

                HttpResponseMessage response =  client.DeleteAsync("http://localhost:57135/api/Employees/3").Result;
                Console.WriteLine("{0}\t{1}", "StatusCode:", response.StatusCode);
                Console.ReadKey();

            }
        }
    }

Result

 

  

 

Reflection in SQL Table

 

  

I hope you enjoyed this article. Your valuable feedback, question, or comments about this article are always welcomed.