Why is my Post method disallowed?

Question

I've been successfully using this method to GET REST data:

private JArray GetRESTData(string uri)
{
    try
    {
        var webRequest = (HttpWebRequest)WebRequest.Create(uri);
        var webResponse = (HttpWebResponse)webRequest.GetResponse();
        var reader = new StreamReader(webResponse.GetResponseStream());
        string s = reader.ReadToEnd();
        return JsonConvert.DeserializeObject<JArray>(s);
    }
    catch // This method crashes if only one json "record" is found - try this:
    {
        try
        {
            MessageBox.Show(GetScalarVal(uri));
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }
    return null;
}

Between the webRequest and webResponse assignments, I added this:

if (uri.Contains("Post"))
{
    webRequest.Method = "POST";
}

...and called it with this URI:

http://localhost:28642/api/Departments/PostDepartment/42/76TrombonesLedTheZeppelin

Although I have a Post method that corresponds to it:

Controller

[Route("api/Departments/PostDepartment/{accountid}/{name}/{dbContext=03}")]
public void PostDepartment(string accountid, string name, string dbContext)
{
    _deptsRepository.PostDepartment(accountid, name, dbContext);
}

Repository

public Department PostDepartment(string accountid, string name, string dbContext)
{
    int maxId = departments.Max(d => d.Id);
    // Add to the in-memory generic list:
    var dept = new Department {Id = maxId + 1, AccountId = accountid, Name = name};
    departments.Add(dept);
    // Add to the "database":
    AddRecordToMSAccess(dept.AccountId, dept.Name, dbContext);
    return dept;
}

...it fails with, "The remote server returned an error: (405) Method Not Allowed."

Why is it not allowed?

UPDATE

Based on what I found here: http://blog.codelab.co.nz/2013/04/29/405-method-not-allowed-using-asp-net-web-api/, I added this to Web.Config:

  <validation validateIntegratedModeConfiguration="false" />
    <modules runAllManagedModulesForAllRequests="true">
      <remove name="WebDAVModule" />
    </modules>
    <handlers>
      <remove name="WebDAV" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT" 
type="System.Web.Handlers.TransferRequestHandler" resourceType="Unspecified" requireAccess="Script" 
preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>

...so that it went from this:

<system.webServer>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" 
type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
  </system.webServer></configuration>

...to this:

<system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <modules runAllManagedModulesForAllRequests="true">
      <remove name="WebDAVModule" />
    </modules>
    <handlers>
      <remove name="WebDAV" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT" 
type="System.Web.Handlers.TransferRequestHandler" resourceType="Unspecified" requireAccess="Script" 
preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
</system.webServer></configuration>

....but it made no diff.

UPDATE 2

It doesn't even make it to the call in the Controller:

        [HttpPost]
[System.Web.Http.Route("api/Departments/PostDepartment/{accountid}/{name}/{dbContext=03}")]
        public void PostDepartment(string accountid, string name, string dbContext)
        {
            _deptsRepository.PostDepartment(accountid, name, dbContext);
        }

I have a breakpoint inside it that's not reached...???

UPDATE 3

VirtualBlackFox's last comment was the one that did the trick. I just changed my "is it a post?" in my client code to the following:

if (uri.Contains("Post"))
{
    webRequest.Method = "POST";
    webRequest.ContentLength = 0; // <-- This line is all I added
}

...and now it works.

Answer 1

I don't do Asp.Net but i'll guess that you need to specify the HttpPost attribute as can be seen in Attribute Routing / HTTP Methods documentation :

[HttpPost]
[Route("api/Departments/PostDepartment/{accountid}/{name}/{dbContext=03}")]
public void PostDepartment(string accountid, string name, string dbContext)
{
    _deptsRepository.PostDepartment(accountid, name, dbContext);
}

---

Small sample that work on my PC :

TestController.cs:

using System.Web.Http;

namespace WebApplication2.Controllers
{
    public class TestController : ApiController
    {
        [HttpPost]
        [Route("api/Departments/PostDepartment/{accountid}/{name}/{dbContext=03}")]
        public string PostDepartment(string accountid, string name, string dbContext)
        {
            return accountid + name + dbContext;
        }
    }
}

Test.html :

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-2.0.3.min.js"></script>
    <script>
        $(function () {
            $.ajax("api/Departments/PostDepartment/accountid/name/dbContext", {
                type: 'POST', success: function (data) {
                    $('#dest').text(data);
                }
            });
        });
    </script>
</head>
<body>
    <div id="dest"></div>
</body>
</html>

Sample program to call the service in C# :

namespace ConsoleApplication1
{
    using System;
    using System.IO;
    using System.Net;
    using Newtonsoft.Json;

    class Program
    {
        static void Main()
        {
            Console.WriteLine(GetRestData(@"http://localhost:52833//api/Departments/PostDepartment/42/76TrombonesLedTheZeppelin"));
            Console.ReadLine();
        }

        private static dynamic GetRestData(string uri)
        {

            var webRequest = (HttpWebRequest)WebRequest.Create(uri);
            webRequest.Method = "POST";
            webRequest.ContentLength = 0;
            var webResponse = (HttpWebResponse)webRequest.GetResponse();
            var reader = new StreamReader(webResponse.GetResponseStream());
            string s = reader.ReadToEnd();
            return JsonConvert.DeserializeObject<dynamic>(s);

        }
    }
}