I have a Windows 8 Metro app pulling data from SalesForce through the REST API, which works for most queries. However, the routes to download attachments from records do not seem to work. As an alternative, I decided to try out the SOAP API, which seems to have better documentation.
Unfortunately, I have not been able to get the SOAP API to work on a Metro app because the SforceService object is not available when the WSDL file is added as a service reference. The most common solution(e.g. here, here, and here) is to add the WSDL as a web reference, however this is not possible for a Metro app. So, has anyone successfully used the SOAP API from a Metro app, and if so how did you get around the SforceService problem? Is there another way to add the WSDL that keeps SforceService?
For reference, I am using C# in Visual Studio Enterprise 2015, targeting .NET 4.6 with project type Windows 8.1 (Metro app). I am well aware of the process for adding a web service, and that works fine for a console application, but adding a web service is not an option for Metro apps.
Edit: Steps taken so far - Have added SalesForce WSDL file (both Enterprise and Partner) as a service reference, found that SforceService was not available. Tested with a console app and found that adding as a web service works correctly. Common answers to this issue are to add as a web service (not possible for Metro app), or to target .NET 3.5 (not practical for this project). I have not provided detail about the file issues in the REST API as my question here is about the SOAP API, I've only mentioned those problems as background for why I am trying to use the SOAP API.