A file to open connections to a sharepoint site from a desktop application. This is intended to run on the application server.

SPConnection.cs

using System;
using System.Text;
using System.Web;
using Microsoft.SharePoint;

    public class SPConnection
    {
        private SPSite _site;
        private SPWeb _web;
        private string _siteUrl;
        private string _loginName;

        /// <summary>
        /// Gets the SP Web.
        /// </summary>
        /// <value>The sp web.</value>
        public SPWeb SpWeb
        {
            get { return _web; }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="SPConnection"/> class.
        /// </summary>
        /// <param name="siteUrl">The site URL.</param>
        /// <param name="loginName">Name of the login.</param>
        public SPConnection(string siteUrl, string loginName)
        {
            this._siteUrl = siteUrl;
            this._loginName = loginName;
        }

        /// <summary>
        /// Opens the connection to the sharepoint site.
        /// </summary>
         public void OpenConnection()
        {
            SPSite spSite = new SPSite(_siteUrl);
            SPUser user = spSite.RootWeb.AllUsers[_loginName];
            SPUserToken userToken = spSite.UserToken;

            _site = new SPSite(_siteUrl, userToken);
            _web = _site.OpenWeb();
            spSite.Dispose();

            // Ensure HttpContext.Current
            if (HttpContext.Current == null)
            {
                HttpRequest request = new HttpRequest("", _web.Url, "");
                HttpContext.Current = new HttpContext(request,
                  new HttpResponse(System.IO.TextWriter.Null));
            }

            // SPContext is based on SPControl.GetContextWeb(), which looks here
            if (HttpContext.Current.Items["HttpHandlerSPWeb"] == null)
                HttpContext.Current.Items["HttpHandlerSPWeb"] = _web;
        }

         /// <summary>
         /// Closes the connection to the sharepoint site.
         /// </summary>
        public void CloseConnection()
        {
            _web.Dispose();
            _site.Dispose();
        }
    }