C# รบกวนสอบถามการใช้งาน EPplus สำหรับสร้าง Excel หน่อยนะครับ ^ ^"

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Data;
using System.IO;

using OfficeOpenXml;
using OfficeOpenXml.Style;

namespace ECIM.Export
{
    public partial class Epplus
    {
        private string _filePath;

        public Epplus(string FilePath)
        {
            _filePath = FilePath;
        }

        #region ===================== Export =======================
        public bool Export(DataSet DsData)
        {
            int i = 1;
            ExcelPackage xlPackage = new ExcelPackage();

            foreach (DataTable DtData in DsData.Tables)
            {
                string sheetName = (DtData.TableName != string.Empty) ? DtData.TableName : string.Format("Sheet{0}", i.ToString());

                AddSheet(xlPackage, sheetName, DtData);
                i++;
            }

            return Save(xlPackage.GetAsByteArray());
        }

        public bool Export(DataTable DtData)
        {
            ExcelPackage xlPackage = new ExcelPackage();

            string sheetName = (DtData.TableName != string.Empty) ? DtData.TableName : "Sheet1";

            AddSheet(xlPackage, sheetName, DtData);

            return Save(xlPackage.GetAsByteArray());
        }

        public bool Export(DataSet DsData, string TableName)
        {
            return Export(DsData.Tables[TableName]);
        }

        public bool ExportWithSum(List<DataSet> DataList)
        {
            int i = 1;
            ExcelPackage xlPackage = new ExcelPackage();

            foreach (DataSet DsData in DataList)
            {
                string sheetName = (DsData.DataSetName != string.Empty) ? DsData.DataSetName : string.Format("Sheet{0}", i.ToString());

                AddSheet(xlPackage, sheetName, DsData, true);
                i++;
            }

            return Save(xlPackage.GetAsByteArray());
        }

        public bool ExportWithSum(DataSet DsData)
        {
            int i = 1;
            ExcelPackage xlPackage = new ExcelPackage();

            foreach (DataTable DtData in DsData.Tables)
            {
                string sheetName = (DtData.TableName != string.Empty) ? DtData.TableName : string.Format("Sheet{0}", i.ToString());

                AddSheet(xlPackage, sheetName, DtData, true);
                i++;
            }

            return Save(xlPackage.GetAsByteArray());
        }

        public bool ExportWithSum(DataTable DtData)
        {
            ExcelPackage xlPackage = new ExcelPackage();

            string sheetName = (DtData.TableName != string.Empty) ? DtData.TableName : "Sheet1";

            AddSheet(xlPackage, sheetName, DtData, true);

            return Save(xlPackage.GetAsByteArray());
        }

        public bool ExportWithSum(DataSet DsData, string TableName)
        {
            return ExportWithSum(DsData.Tables[TableName]);
        }

        protected void AddSheet(ExcelPackage xlPackage, string SheetName, DataSet DsData)
        {
            AddSheet(xlPackage, SheetName, DsData, false);
        }

        protected void AddSheet(ExcelPackage xlPackage, string SheetName, DataSet DsData, bool SumData)
        {
            ExcelWorksheet xlSheet = xlPackage.Workbook.Worksheets.Add(SheetName);

            int startRow = 1;

            foreach (DataTable DtData in DsData.Tables)
            {
                FillData(xlSheet, DtData, startRow, SumData, DtData.TableName);

                startRow += DtData.Rows.Count + 3 + ((SumData) ? 1 : 0);
            }
        }

        protected void AddSheet(ExcelPackage xlPackage, string SheetName, DataTable DtData)
        {
            AddSheet(xlPackage, SheetName, DtData, false);
        }

        protected void AddSheet(ExcelPackage xlPackage, string SheetName, DataTable DtData, bool SumData)
        {
            ExcelWorksheet xlSheet = xlPackage.Workbook.Worksheets.Add(SheetName);

            FillData(xlSheet, DtData, 1, SumData);
        }

        protected void FillData(ExcelWorksheet xlSheet, DataTable DtData, int StartRow)
        {
            FillData(xlSheet, DtData, StartRow, false);
        }

        protected void FillData(ExcelWorksheet xlSheet, DataTable DtData, int StartRow, bool SumData)
        {
            FillData(xlSheet, DtData, StartRow, SumData, string.Empty);
        }

        protected void FillData(ExcelWorksheet xlSheet, DataTable DtData, int StartRow, bool SumData, string HeaderName)
        {
            int headerLength = (HeaderName != string.Empty) ? 1 : 0;

            int rowCount = DtData.Rows.Count;
            int colomnCount = DtData.Columns.Count;

            if (HeaderName != string.Empty)
            {
                xlSheet.Cells[StartRow, 1].Value = HeaderName;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Merge = true;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;

                //font
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Font.SetFromFont(new System.Drawing.Font("MS Sans Serif", 10, System.Drawing.FontStyle.Bold));

                //background color
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Fill.PatternType = ExcelFillStyle.Solid;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.LightYellow);

                //border
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Top.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Right.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Bottom.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Left.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Top.Color.SetColor(System.Drawing.Color.LightGray);
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Right.Color.SetColor(System.Drawing.Color.LightGray);
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Bottom.Color.SetColor(System.Drawing.Color.LightGray);
                xlSheet.Cells[StartRow, 1, StartRow, colomnCount].Style.Border.Left.Color.SetColor(System.Drawing.Color.LightGray);
            }

            xlSheet.Cells[StartRow + headerLength, 1].LoadFromDataTable(DtData, true);

            IEnumerable<int> dateColumns = from DataColumn d in DtData.Columns
                                           where d.DataType == typeof(DateTime) || d.ColumnName.Contains("Date")
                                           orderby d.Ordinal ascending
                                           select d.Ordinal + 1;

            IEnumerable<int> doubleColumn = from DataColumn d in DtData.Columns
                                            where d.DataType == typeof(double) || d.DataType == typeof(float)
                                            orderby d.Ordinal ascending
                                            select d.Ordinal + 1;

            if (DtData.Rows.Count > 0)
            {
                foreach (int dc in dateColumns)
                {
                    xlSheet.Cells[StartRow + headerLength + 1, dc, StartRow + headerLength + rowCount, dc].Style.Numberformat.Format = "dd/MM/yyyy";
                }

                foreach (int dc in doubleColumn)
                {
                    xlSheet.Cells[StartRow + headerLength + 1, dc, StartRow + headerLength + rowCount, dc].Style.Numberformat.Format = "#,##0.00";
                }

                //font
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Font.SetFromFont(new System.Drawing.Font("MS Sans Serif", 10, System.Drawing.FontStyle.Regular));

                //background color
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength, colomnCount].Style.Fill.PatternType = ExcelFillStyle.Solid;
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength, colomnCount].Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.LightYellow);

                //border
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Top.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Right.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Bottom.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Left.Style = ExcelBorderStyle.Thin;
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Top.Color.SetColor(System.Drawing.Color.LightGray);
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Right.Color.SetColor(System.Drawing.Color.LightGray);
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Bottom.Color.SetColor(System.Drawing.Color.LightGray);
                xlSheet.Cells[StartRow + headerLength, 1, StartRow + headerLength + rowCount, colomnCount].Style.Border.Left.Color.SetColor(System.Drawing.Color.LightGray);

                if (SumData)
                {
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1].Value = "รวม";
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1].Style.Font.SetFromFont(new System.Drawing.Font("MS Sans Serif", 10, System.Drawing.FontStyle.Bold));
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;

                    if (doubleColumn.First() > 1)
                        xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, doubleColumn.First() - 1].Merge = true;

                    foreach (int dc in doubleColumn)
                    {
                        xlSheet.Cells[StartRow + headerLength + rowCount + 1, dc, StartRow + headerLength + rowCount + 1, dc].Formula = string.Format("SUM({0}:{1})", xlSheet.Cells[StartRow + headerLength, dc].Address, xlSheet.Cells[StartRow + headerLength + rowCount, dc].Address);
                        xlSheet.Cells[StartRow + headerLength + rowCount + 1, dc, StartRow + headerLength + rowCount + 1, dc].Style.Numberformat.Format = "#,##0.00";
                    }

                    //background color
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Fill.PatternType = ExcelFillStyle.Solid;
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.LightYellow);

                    //border
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Top.Style = ExcelBorderStyle.Thin;
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Right.Style = ExcelBorderStyle.Thin;
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Bottom.Style = ExcelBorderStyle.Thin;
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Left.Style = ExcelBorderStyle.Thin;
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Top.Color.SetColor(System.Drawing.Color.LightGray);
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Right.Color.SetColor(System.Drawing.Color.LightGray);
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Bottom.Color.SetColor(System.Drawing.Color.LightGray);
                    xlSheet.Cells[StartRow + headerLength + rowCount + 1, 1, StartRow + headerLength + rowCount + 1, colomnCount].Style.Border.Left.Color.SetColor(System.Drawing.Color.LightGray);

                    //Auto Fit Columns
                    xlSheet.Cells[StartRow, 1, StartRow + headerLength + rowCount + 1, colomnCount].AutoFitColumns();
                }
            }
        }

        protected bool Save(byte[] buffer)
        {
            bool result;

            if (File.Exists(_filePath))
            {
                File.Delete(_filePath);
            }

            try
            {
                File.WriteAllBytes(_filePath, buffer);

                result = true;
            }
            catch
            {
                result = false;
            }  

            return result;
        }
        #endregion
    }
}