ASP.NET MVC 4 – Convert an existing Web Application Project to Web Api project

I do not have much time to provide the background, suffice it should be to say that I decided to adopt ASP.NET 4.0 MVC Web Api in a major way today after being in evaluation mode for some days (4.0 MVC was still in Beta as I wrote this).

And so I needed to convert my existing Web Application (WAP) projects to Web Api projects. And I followed a very simple approach to figure out the same. I created a new solution with 2 projects, one a WAP project and the other a Web Api project. I removed all default configuration from both the projects leaving only the absolute essentials behind.

I then a used a Diff tool (Tortoise SVN’s diff viewer) to find the differences between the 2 project types and upgrade my WAP project to a Web Api project.

In the end, it was some very simple steps:

1. Unload the WAP project in Visual Studio.
2. Right-click it and open the project file for editing.
3. Empty out the <ProductVersion> element from the WAP project’s file (it might already be empty, that should be okay). Do not remove this element, just ensure its contents are empty.
4. Overwrite the <ProjectTypeGuids> element with the following:
   {syntaxhighlighter brush: xml;fontsize: 100; first-line: 1; }<ProjectTypeGuids>{E3E379DF-F4C6-4180-9B81-6769533ABE47};{349c5851-65df-11da-9384-00065b846f21};{fae04ec0-301f-11d3-bf4b-00c04f79efbc}</ProjectTypeGuids>
   {/syntaxhighlighter} 
5. Right-click and open the project again in Visual Studio.

That should be it. Your project should now be a Web Api project allowing adding MVC 4 items.

You would need to add reference to assemblies specific to Web Api/MVC 4 still. Either you can do it manually using the “Add Reference” dialog, or paste the following assembly references in your project file:

    <Reference Include="EntityFramework">
      <HintPath>..\packages\EntityFramework.4.1.10331.0\lib\net40\EntityFramework.dll</HintPath>
    </Reference>
    <Reference Include="Microsoft.Web.Infrastructure, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\Microsoft.Web.Infrastructure.1.0.0.0\lib\net40\Microsoft.Web.Infrastructure.dll</HintPath>
    </Reference>
    <Reference Include="System.Data.Entity" />
    <Reference Include="System.Json, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\System.Json.4.0.20126.16343\lib\net40\System.Json.dll</HintPath>
    </Reference>
    <Reference Include="System.Net.Http, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\System.Net.Http.2.0.20126.16343\lib\net40\System.Net.Http.dll</HintPath>
    </Reference>
    <Reference Include="System.Net.Http.Formatting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\System.Net.Http.Formatting.4.0.20126.16343\lib\net40\System.Net.Http.Formatting.dll</HintPath>
    </Reference>
    <Reference Include="System.Net.Http.WebRequest, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\System.Net.Http.2.0.20126.16343\lib\net40\System.Net.Http.WebRequest.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Entity" />
    <Reference Include="System.Web.ApplicationServices" />
    <Reference Include="System.ComponentModel.DataAnnotations" />
    <Reference Include="System.Web.Helpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetWebPages.Core.2.0.20126.16343\lib\net40\System.Web.Helpers.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetWebApi.Core.4.0.20126.16343\lib\net40\System.Web.Http.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Http.Common, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\System.Web.Http.Common.4.0.20126.16343\lib\net40\System.Web.Http.Common.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Http.WebHost, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetWebApi.4.0.20126.16343\lib\net40\System.Web.Http.WebHost.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Mvc, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetMvc.4.0.20126.16343\lib\net40\System.Web.Mvc.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Optimization">
      <HintPath>..\packages\Microsoft.Web.Optimization.1.0.0-beta\lib\net40\System.Web.Optimization.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Providers">
      <HintPath>..\packages\System.Web.Providers.Core.1.0\lib\net40\System.Web.Providers.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetRazor.Core.2.0.20126.16343\lib\net40\System.Web.Razor.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetWebPages.Core.2.0.20126.16343\lib\net40\System.Web.WebPages.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.WebPages.Deployment, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetWebPages.Core.2.0.20126.16343\lib\net40\System.Web.WebPages.Deployment.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\AspNetWebPages.Core.2.0.20126.16343\lib\net40\System.Web.WebPages.Razor.dll</HintPath>
    </Reference>
    <Reference Include="System.Web.Abstractions" />
    <Reference Include="System.Web.Routing" />

This blog post provides an excellent approach to bin deploy MVC assemblies as part of your web application without requiring to install Web Api on the deployment server.

UPDATE:

• Mar 15, 2012 – If you do not want to manually add required assembly references to your project file, just right-click the project and add a “MVC 4 Web Api Controller” class to your project from the “New Item” dialog. Visual Studio should then add all required assembly references for MVC 4 to your project automatically.