How to Add API controller (Web API 2) in Asp.Net (aspx) application C#

Question

I have a asp.net (aspx) c# web application on .net framework 4.5, I have to create a web api in this application that will consume in third party CMS(Infusionsoft) Http POST campaign.

Answer 1

To add webapi controller in asp.net C# application

Step 1: Add new webapi controller using Add New Item process

Step 2: Added PaymentController

 public class PaymentController : ApiController
    {
        // GET api/<controller>
        public IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }

        // GET api/<controller>/5
        public string Get(int id)
        {
            return "value";
        }

        // POST api/<controller>
        public void Post([FromBody]string value)
        {
        }

        // PUT api/<controller>/5
        public void Put(int id, [FromBody]string value)
        {
        }

        // DELETE api/<controller>/5
        public void Delete(int id)
        {
        }
    }

Step 3: Add Routing information in Application_stat methd inside Global.asax.cs file

Add Using namespaces:

using System.Web.Http;
using System.Web.Routing;



 protected void Application_Start(Object sender, EventArgs e)
        {
            RouteTable.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = System.Web.Http.RouteParameter.Optional }
                );
        }

Step 4: Run application and it will raise below exception:

Attempt by security transparent method 'DebtFREE.Global.Application_Start(System.Object, System.EventArgs)' to access security critical field 'System.Web.Http.RouteParameter.Optional' failed. Assembly 'DebtFREE, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' is marked with the AllowPartiallyTrustedCallersAttribute, and uses the level 2 security transparency model. Level 2 transparency causes all methods in AllowPartiallyTrustedCallers assemblies to become security transparent by default, which may be the cause of this exception.

Step 5: Go to AssemblyInfo.cs (Bin/Properties/AssemblyInfo.cs) and comment below line. [assembly: AllowPartiallyTrustedCallers]

Step 6: Cheers, run application and browse url: http://localhost:2071/api/payment API is wokring togather aspx (asp.net) application.