var list = new List<Pr20Model>
{
        new Pr20Model
        {
            Fullname = "AAA", Mobile = "123456798123"
        },
        new Pr20Model
        {
            Fullname = "BBB", Mobile = "234"
        }
};
var bytes = ExcelHelper.ObjectToExcelBytes(list, ExcelType.Xlsx);
// model
[ExcelTitle("SheetX")]
public class Pr20Model
{
    [ExcelColumn("姓名", CellFontColor = ExcelStyleColor.Red)]
    public string Fullname { get; set; }

    [ExcelColumn("手机",
        HeaderFontFamily = "宋体",
        HeaderBold = true,
        HeaderFontHeight = 30,
        HeaderItalic = true,
        HeaderFontColor = ExcelStyleColor.Blue,
        HeaderUnderline = true,
        HeaderAlignment = HorizontalAlignment.Right,
        //cell
        CellAlignment = HorizontalAlignment.Justify
    )]
    public string Mobile { get; set; }
}

    public class ReportModel
    {
        [Excel("My Title",Order=1)]
        public string Title { get; set; }
        [Excel("User Name",Order=2)]
        public string Name { get; set; }
    }

      var models = new List<ReportModel>
            {
                new ReportModel{Name="a",Title="b"},
                new ReportModel{Name="c",Title="d"},
                new ReportModel{Name="f",Title="e"}
            };

      var exporter = new ExcelExporter();
      var bytes = exporter.ObjectToExcelBytes(models);
      File.WriteAllBytes("C:\\demo.xls", bytes);

      var importer = new ExcelImporter();
      IEnumerable<ReportModel> result = importer.ExcelToObject<ReportModel>("c:\\demo.xls");
      // also can use bytes
      //IEnumerable<ReportModel> result = importer.ExcelToObject<ReportModel>(bytes);