I am working on a Windows 8.1 app where I would like the ability to download files directly from SharePoint. We currently still have SharePoint 2010 here. Since I am developing for a Win 8.1 app, I am using the dll files found in C:\Program Files\Common Files\microsoft shared\Web Server Extensions\16\ISAPI. The dll's I have referenced are:

Microsoft.SharePoint.Client.Portable

Microsoft.SharePoint.Client.Runtime.Portable

Microsoft.SharePoint.Client.Runtime.WindowsStore

I tried using the code below to download the file

        public static async void DownloadFolderContents(string SharePointFolderPath, string SavePath)
        {
            try
            {
                // Create the ClientContext for the TMT site.
                using (ClientContext clientContext = new ClientContext(SharePointUrl))
                {
                    StorageFolder docLibrary = KnownFolders.DocumentsLibrary;
                    StorageFolder saveFolder = await docLibrary.CreateFolderAsync(SavePath, CreationCollisionOption.OpenIfExists);

                    // Get the website for the client context.
                    Web website = clientContext.Web;

                    // Set the project folder based on the SharePointFolderPath
                    Folder projectFolder = website.GetFolderByServerRelativeUrl(SharePointFolderPath);
                                        
                    // Load the website and folder.
                    clientContext.Load(website);                    
                    clientContext.Load(projectFolder, p => p.Files, p => p.Folders);

                    await clientContext.ExecuteQueryAsync();

                    // Downlaod each file in the folder.
                    foreach (var file in projectFolder.Files)
                    {
                        string fileRef = file.ServerRelativeUrl;
                        string[] fileParts = fileRef.Split('.');

                        // Only download files that aren't prohibited by type.
                        if (Array.IndexOf(ProhibitedFileTypes, fileParts[fileParts.Length - 1]) < 0)
                        {
                            StorageFile saveFile = await saveFolder.CreateFileAsync(file.Name, CreationCollisionOption.ReplaceExisting);
                            
                            clientContext.Load(file);

                            ClientResult<Stream> sharePointFile = file.OpenBinaryStream();

                            await clientContext.ExecuteQueryAsync();
                            
                            //using (Stream sharePointStream = sharePointFile.Value)
                            //{
                            //    using (var fileStream = await saveFile.OpenStreamForWriteAsync())
                            //    {
                            //        await sharePointStream.CopyToAsync(fileStream);
                            //    }
                            //}
                        }
                    }
                }
            }
            catch (Exception)
            {   
                throw;
            }
        }

When I do this, I get an error that File.OpenBinaryStream doesn't exist which I believe is because we (still) have SharePoint 2010. If I try to use the older dlls, it won't compile because they require Web Services. Does anyone know a solution for this? I've searched around existing posts similar to this topic but none of their solutions seem to work. I believe that it's because they are either using SharePoint 2013 or newer or aren't working on a Windows Store App.