title: How to add the "Windows.Web.Http" to your project?
body: <p>I am in the process of changing my Windows 8.1 store application to use TLS 1.2. This was required by the client who recently moved all Web APIs to HTTPS and forced the entire traffic network to use TLS 1.2. My store app started having communication issues with the Web API and the reason is that it is not forcing its calls to the Web API to use TLS 1.2. After some research, I saw that the System.Net.Http classes I used for the communication (HttpClient and HttpClientHandler) are not going to help me. I need to use similar API from Windows.Web.Http. From my readings, I also saw that I need to retarget all my projects in the solution to .NET Framework 4.6 and Windows Universal 10.0. That triggered a lot of changes (for some projects I had to uninstall all NuGet Packages before I changed the targets). Anyway, I am finally at the point where I am ready to start using the HttpClient class from Windows.Web.Http namespace. The problem is that I can't find which NuGet package I need to install to bring this namespace into my project. Simply entering "using Windows.Web.Http" is not enough as the namespace is not known.</p>
  
  <p>Any ideas on how to add that API to my project?</p>
  
  <p>TIA,
  Ed</p>
  
  <p>Edit 1: For Sunteen, to see how my project has its targets configured:</p>
  
  <p><a href="https://i.stack.imgur.com/cjh0e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cjh0e.png" alt="enter image description here"></a></p>
  
  <p>When I tried to add this line "using Windows.Web.Http", Windows appears with the red squiggly line underneath.</p>
  
  <p>Edit 2: Here is how the Library tab looks like in the Project's settings:
  <a href="https://i.stack.imgur.com/aJEhu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aJEhu.png" alt="enter image description here"></a></p>
  
  <p>Edit 3: My Windows Store 8.1 app uses a Portable Class Library that incorporates a Web API Client which is making all RESTful calls:</p>
  
  <p><a href="https://i.stack.imgur.com/WZ1b9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WZ1b9.png" alt="enter image description here"></a></p>
  
  <p>Is the type of the library (Portable) the wrong type?</p>
  
  <p>Edit4 (for Sunteen): Hi Sunteen, The Tablet.WebApi.Client was just a Class Library project that encapsulated all the functionality needed to call a RESTful Web API. The application that makes use of that library is a Windows 8.1 Store application. I have since changed all Class Libraries to be Windows 8.1 Class Library, as opposed to Portable Class Library as per my original screenshot. Here is the entire structure of the solution:</p>
  
  <p><a href="https://i.stack.imgur.com/EGJMW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EGJMW.png" alt="enter image description here"></a></p>
  
  <p>Since the Tablet.WebApi.Client library is the one that contains the functionality used to call the RESTful Web API, it is here where I needed to replace the System.Net.Http.HttpClient class with the Windows.Web.Http version.</p>
  
  <p>I am still confused about the type of project my XXXXXTabletApp needs to be. I can retarget all my class libraries to use .NET Framework 4.6 and Windows Universal 10.0 but I cannot do the same with the XXXXXTabletApp project since that one is a clear Windows 8.1 Store application. I guess the solution is to create a new UWL application and that will be able to link with all my retargeted class libraries. Is this approach correct?</p>