Конвертировать XLSX в XLS

    // For complete examples and data files, please go to https://github.com/aspose-cells-cloud/aspose-cells-cloud-dotnet/
    string name = "Book1.xlsx";
    string format = "xls";
    string password = null;
    string outPath = null;
    string storageName = null;
    string destFile = "Book1.xls";
    CellsApi cellsApi = new CellsApi(Environment.GetEnvironmentVariable("ProductClientId"), Environment.GetEnvironmentVariable("ProductClientSecret"));
    using (Stream stream = cellsApi.CellsWorkbookPutConvertWorkbook(File.OpenRead(name), format, password, outPath, storageName))
    {
        using (Stream outStream = File.OpenWrite(destFile))
        {
            stream.CopyTo(outStream);
        }
    }