public static async void Save(this C1WordDocument doc)
        {
            FileSavePicker picker = new FileSavePicker();

            picker.FileTypeChoices.Add(Strings.FileTypeChoicesTip, new List <string>()
            {
                ".docx"
            });
            picker.FileTypeChoices.Add(Strings.AlternateFileTypeChoicesTip, new List <string>()
            {
                ".rtf"
            });
            picker.DefaultFileExtension   = ".docx";
            picker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
            StorageFile file = await picker.PickSaveFileAsync();

            if (file != null)
            {
                await doc.SaveAsync(file, file.Name.ToLower().EndsWith(".rtf")?FileFormat.Rtf : FileFormat.OpenXml);

                MessageDialog dlg = new MessageDialog(Strings.SaveLocationTip + " " + file.Path, "WordSamples");
                dlg.Commands.Add(new UICommand("Open", new UICommandInvokedHandler((args) =>
                {
                    // to open the created file (using file extension)
                    var success = Launcher.LaunchFileAsync(file);
                })));
                dlg.Commands.Add(new UICommand("Cancel"));
                dlg.CancelCommandIndex = 2;
                await dlg.ShowAsync();
            }
        }
        public static async Task <MemoryStream> SaveToStream(this C1WordDocument doc)
        {
            var ms = new MemoryStream();

            using (var imas = new InMemoryRandomAccessStream())
            {
                await doc.SaveAsync(imas.AsStream(), FileFormat.OpenXml);
            }
            return(ms);
        }