Object Parameters and Object Return C# WebService to Android

Perhaps a concrete example is also useful. Assuming you can invoke AndroidHttpClient to do an HttpPost, you can leverage a simple asp.net mvc controller action to process the post (as xml) and return xml (or whatever) accordingly for you to parse.

For your asp.net mvc action, try something like this (routed to http://foo.com/Something/ProcessSomething):

...

[ ValidateInput(false)
]
public class SomethingController : Controller
{
  ...

  [ HttpPost
  ]
  public ActionResult ProcessSomething(SomeParameters Parameters, String Options)
  {
    ...

    String sProcessed = Parameters.Descriptor.ParamA + Parameters.Descriptor.ParamB;

    ...

    return this.Content
      ( String.Format
        ( "<result><processed>{0}</processed></result>"
        , sProcessed
        )
      , "text/xml"
      );
  }

  /// <summary>
  /// Description of a view model instance.
  /// </summary>

  [ XmlRoot("something")
  ]
  public class SomethingDescriptor
  {
    private String _ParamA = String.Empty;
    private String _ParamB = String.Empty;

    [ XmlElement("paramA")
    ]
    public String ParamA
    {
      set
      {
        this._ParamA = value;
      }
      get
      {
        return this._ParamA;
      }
    }

    [ XmlElement("paramB")
    ]
    public String ParamB
    {
      set
      {
        this._ParamB = value;
      }
      get
      {
        return this._ParamB;
      }
    }

  }

  /// <summary>
  /// View parameter deserializer.
  /// </summary>

  public class SomethingParameters
  {
    private SomethingDescriptor _Descriptor = new SomethingDescriptor();

    public SomethingDescriptor Descriptor
    {
      get
      {
        return this._Descriptor;
      }
    }

    public String Something
    {
      set
      {
        try
        {
          using (StringReader sR = new StringReader(value))
          {
            XmlSerializer xS = new XmlSerializer(typeof(SomethingDescriptor));

            this._Descriptor = xS.Deserialize(sR) as SomethingDescriptor;
          }
        }
        catch
        {
        }
      }
      get
      {
        return String.Empty;
      }
    }

  }

}

Your android app would post a variable such as "Something=<something><paramA>this is pA</paramA><paramB>this is paramB</paramB></something>" to http://foo.com/Something/ProcessSomething and get back xml that it can use to render something to the user.