Convert Excel Spreadsheets to CSV and CSV to XLS/XLSX using C#

ConvertCsvToExcel.cs

// Convert CSV files to XLS/XLSX format in C#
string inputFile = @"path/comma-sparated-values.csv";
string outputFile = @"path/spreadsheet.xlsx";

Contracts.Func<LoadOptions> getLoadOptions = () => new CsvLoadOptions
{
    Separator = ','
};

using (Converter converter = new Converter(inputFile))
{
    SpreadsheetConvertOptions options = new SpreadsheetConvertOptions();
    converter.Convert(outputFile, options);
}

ConvertExcelToCSV.cs

// Convert Excel Spreadsheets to Comma Separated Values CSV format in C#
string inputFile = @"path/spreadsheet.xlsx";
string outputFile = @"path/comma-sparated-values.csv";

using (Converter converter = new Converter(inputFile))
{
    SpreadsheetConvertOptions options = new SpreadsheetConvertOptions
    {
        PageNumber = 2,
        PagesCount = 1,
        Format = SpreadsheetFileType.Csv // Specify the conversion format
    };
    converter.Convert(outputFile, options);
}