using NPOI.HSSF.UserModel;

using NPOI.SS.UserModel;

using NPOI.XSSF.UserModel;

using System;

using System.Collections.Generic;

using System.Data;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Common

{

    public static class Import

    {

        /// <summary>

        /// 获取导入的Excel的列名（第一行Titile）

        /// </summary>

        /// <returns></returns>

        public static List<string> GetFieldNames(string filePath)

        {

            ISheet sheet = GetSheet(filePath);

            List<string> filedNameList = new List<string>();

            try

            {

                if (sheet != null)

                {

                    IRow firstRow = sheet.GetRow();

                    int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数

                    for (int i = firstRow.FirstCellNum; i < cellCount; ++i)

                    {

                        ICell cell = firstRow.GetCell(i);

                        if (cell != null)

                        {

                            string cellValue = cell.StringCellValue;

                            if (cellValue != null)

                            {

                                filedNameList.Add(cellValue);

                            }

                        }

                    }

                }

            }

            catch (Exception ex)

            {

                throw ex;

            }

            return filedNameList;

        }

        /// <summary>

        /// 将excel中的数据导入到DataTable中

        /// </summary>

        /// <param name="sheetName">excel工作薄sheet的名称</param>

        /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>

        /// <returns>返回的DataTable</returns>

        public static DataTable ExcelToDataTable(string filePath)

        {

            ISheet sheet = GetSheet(filePath);

            DataTable data = new DataTable();

            int startRow = ;

            try

            {

                if (sheet != null)

                {

                    IRow firstRow = sheet.GetRow();

                    int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数

                    for (int i = firstRow.FirstCellNum; i < cellCount; ++i)

                    {

                        ICell cell = firstRow.GetCell(i);

                        if (cell != null)

                        {

                            string cellValue = cell.StringCellValue;

                            if (cellValue != null)

                            {

                                DataColumn column = new DataColumn(cellValue);

                                data.Columns.Add(column);

                            }

                        }

                    }

                    startRow = sheet.FirstRowNum + ;

                    //最后一列的标号

                    int rowCount = sheet.LastRowNum;

                    for (int i = startRow; i <= rowCount; ++i)

                    {

                        IRow row = sheet.GetRow(i);

                        if (row == null) continue; //没有数据的行默认是null　　　　　　　

                        DataRow dataRow = data.NewRow();

                        for (int j = row.FirstCellNum; j < cellCount; ++j)

                        {

                            if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null

                                dataRow[j] = row.GetCell(j).ToString();

                        }

                        data.Rows.Add(dataRow);

                    }

                }

                return data;

            }

            catch (Exception ex)

            {

                throw ex;

            }

        }

        /// <summary>

        /// 获取sheet

        /// </summary>

        /// <param name="filePath"></param>

        /// <returns></returns>

        private static ISheet GetSheet(string filePath)

        {

            ISheet sheet = null;

            MemoryStream memoryStream = CommonHelper.ReadFile(filePath);

            memoryStream.Position = ;

            try

            {

                IWorkbook workbook = null;

                if (filePath.IndexOf(".xlsx") > ) // 2007版本

                {

                    workbook = new XSSFWorkbook(memoryStream);

                }

                else if (filePath.IndexOf(".xls") > ) // 2003版本

                    workbook = new HSSFWorkbook(memoryStream);

                memoryStream.Close();

                memoryStream.Dispose();

                sheet = workbook.GetSheetAt();

                return sheet;

            }

            catch (Exception ex)

            {

                memoryStream.Close();

                memoryStream.Dispose();

                throw ex;

            }

        }

    }

}

using CRM.Models.Base;

using NPOI.HSSF.UserModel;

using NPOI.SS.UserModel;

using System;

using System.Collections.Generic;

using System.Data;

using System.IO;

using System.Linq;

using System.Reflection;

using System.Text;

using System.Threading.Tasks;

namespace  Common.Utils

{

    public class Export

    {

        public static byte[] ExportToExcel<T>(List<T> modelList)

        {

            byte[] resultByte = null;

            IWorkbook workbook = new HSSFWorkbook();//创建Workbook对象

            ISheet sheet = workbook.CreateSheet();

            //填充表头

            IRow dataRow = sheet.CreateRow();

            System.Reflection.PropertyInfo[] ps = typeof(T).GetProperties();

            for (int i = ; i < ps.Count(); i++)

            {

                //object obj = ps[i].GetValue(typeof(T), null);

                string name = ps[i].Name;

                dataRow.CreateCell(i).SetCellValue(name);

            }

            //填充内容

            for (int i = ; i < modelList.Count; i++)

            {

                dataRow = sheet.CreateRow(i + );

                var type = modelList[i].GetType();

                ps = type.GetProperties();

                for (int j = ; j < ps.Count(); j++)

                {

                    object obj = ps[j].GetValue(modelList[i], null);

                    if (obj != null)

                        dataRow.CreateCell(j).SetCellValue(obj.ToString());

                }

            }

            //保存

            using (MemoryStream ms = new MemoryStream())

            {

                workbook.Write(ms);

                resultByte = ms.ToArray();

                ms.Dispose();

            }

            return resultByte;

        }

        /// <summary>

        /// 根据DateTable导出Excel

        /// </summary>

        /// <param name="dt"></param>

        /// <returns></returns>

        public static byte[] ExportToExcel(DataTable dt)

        {

            byte[] resultByte = null;

            IWorkbook workbook = new HSSFWorkbook();//创建Workbook对象

            ISheet sheet = workbook.CreateSheet();

            //填充表头

            IRow dataRow = sheet.CreateRow();

            for (int i = ; i < dt.Columns.Count; i++)

            {

                string name = dt.Columns[i].ColumnName;

                dataRow.CreateCell(i).SetCellValue(name);

            }

            //填充内容

            for (int i = ; i < dt.Rows.Count; i++)

            {

                dataRow = sheet.CreateRow(i + );

                for (int j = ; j < dt.Columns.Count; j++)

                {

                    object obj = dt.Rows[i][j];

                    if (obj != null)

                    {

                        dataRow.CreateCell(j).SetCellValue(obj.ToString());

                    }

                }

            }

            //保存

            using (MemoryStream ms = new MemoryStream())

            {

                workbook.Write(ms);

                resultByte = ms.ToArray();

                ms.Dispose();

            }

            return resultByte;

        }

    }

}