How to upload/download excel files to/from OneDrive using Windows Phone application?

MainPage.xaml
 
private async void BtnGenerateAndUpload_Click(object sender, RoutedEventArgs e)
{
    using (ExcelEngine x1 = new ExcelEngine())
    {
        IApplication x1App = x1.Excel;
        IWorkbook book = x1App.Workbooks.Create(1);
        IWorksheet sheet = book.Worksheets.Create("new");
        sheet.Range["A1"].Text = "Testing";
        
        book.Version = ExcelVersion.Excel2013;
 
        try
        {
            using (IsolatedStorageFileStream outStream = new IsolatedStorageFileStream("Sample.xlsx", FileMode.Create,
   IsolatedStorageFile.GetUserStoreForApplication()))
            {
                await book.SaveAsAsync(outStream);
                book.Close();
            }
            skydrive = new SkyDriveHandler(App.LiveSession, "000000004010FA0B", "InvoiceGenerater");
            
 
            if (await skydrive.UploadFile("Sample.xlsx") == SampleBrowser.Showcase.Invoice.SkyDriveHandler.OperationStatus.Completed)
                MessageBox.Show("Success");
            else
                MessageBox.Show(@"Error while uploading file..! Please try again");
        }
        catch
        {
        }
 
    }
 
 
}
 
private async void ButtonBtnDownload_Click(object sender, RoutedEventArgs e)
{
    skydrive = new SkyDriveHandler(App.LiveSession, "000000004010FA0B", "InvoiceGenerater");
    await skydrive.downloadFile("CheckBookSample.xlsx");
    if(skydrive.FileStream != null)
    {
        using (ExcelEngine x1 = new ExcelEngine())
        {
            IApplication x1App = x1.Excel;
            IWorkbook book = await x1App.Workbooks.OpenAsync(skydrive.FileStream);
            IWorksheet sheet = book.Worksheets["Sheet1"];
 
   
 
            book.Close();
            MessageBox.Show("Success");                
        }
    }
    else
        MessageBox.Show(@"Error while downloading the file..! Please try again");
}
 
//Sky drive handler:
 
public SkyDriveHandler(LiveConnectSession session, string clientID, string folder, string[] scopes = null)
{
    liveSession = session;
    this.clientID = clientID;
    folderName = folder;
 
    if (scopes == null)
    {
        requiredScopes = new string[] { "wl.skydrive_update"};
    }
  
}
 
private async Task SignIn()
{
    if (liveSession == null)
    {
        liveAuth = new LiveAuthClient(clientID);
        liveResult = await liveAuth.InitializeAsync(requiredScopes);
 
        if (liveResult.Status != LiveConnectSessionStatus.Connected)
        {
            liveResult = await liveAuth.LoginAsync(requiredScopes);
        }
 
        liveSession = liveResult.Session;
        liveClient = new LiveConnectClient(liveSession);
    }
}
 
private async Task GetSkyDriveFolder()
{
    if (liveClient == null)
        await SignIn();
 
   LiveOperationResult result = await liveClient.GetAsync("me/skydrive/files/");
    List<object> data = (List<object>)result.Result["data"];
    foreach (IDictionary<string, object> content in data)
    {
        if (content["name"].ToString() == folderName)
        {
            folderID = content["id"].ToString();
        }
    }
    if (folderID == null)
        folderID = await CreateSkydriveFolder();
 
}
 
private async Task<string> CreateSkydriveFolder()
{
    string id = null;
    try
    {
        var folderData = new Dictionary<string, object>();
        folderData.Add("name", folderName);
        LiveOperationResult operationResult =
            await liveClient.PostAsync("me/skydrive", folderData);
        dynamic result = operationResult.Result;
        id = string.Format("{0}", result.id);
    }
    catch
    {
    }
    return id;
}
 
public async Task<OperationStatus> UploadFile(string fileName)
{
    try
    {
        using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication())
        {
            using (var fileStream = store.OpenFile(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                try
                {
                    if (liveClient == null)
                        await GetSkyDriveFolder();
 
                    LiveOperationResult res = await liveClient.UploadAsync(folderID,
                                                fileName,
                                                fileStream,
                                                OverwriteOption.Overwrite
                                                );
                    return OperationStatus.Completed;
                }
                catch
                {
                    return OperationStatus.Failed;
                }
            }
        }
    }
    catch
    {
        return OperationStatus.Failed;
    }
}
public async Task downloadFile(string fileName)
{
    try
    {
        await SignIn();
        LiveOperationResult result = await liveClient.GetAsync("me/skydrive/files");
        List<object> data = (List<object>)result.Result["data"];
        foreach (IDictionary<string, object> content in data)
        {
            if ((((string)content["name"]) == fileName) && (((string)content["type"]) == "file"))
            {
                fileID = content["id"].ToString();
            }
        }
 
        if (fileID != null)
        {
            var downloadOperationResult = await liveClient.DownloadAsync(fileID + "/content");
 
            fileStream = downloadOperationResult.Stream;
        }
 
 
    }
    catch (LiveConnectException ex)
    {
 
    }
}