C# NPOI 导出Execl 工具类

NPOI 导出Execl 自己单独工具类

详见代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NPOI.HPSF;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.SS.Util;
using System.Data;
using System.IO;
using System.Web;
using System.Reflection;
using System.ComponentModel;


namespace NPOIHelper
{
    public class NPOIHelper
    {
        /// <summary>
        /// DataTable导出到Excel文件
        /// </summary>
        /// <param name="dt">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <param name="strFileName">保存位置</param>
        public static void ExportTableExecl(DataTable dt, string strHeaderText, string strFileName)
        {
            using (MemoryStream ms = Exprot(dt, strHeaderText))
            {
                using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                {
                    byte[] data = ms.ToArray();
                    fs.Write(data, 0, data.Length);
                    fs.Flush();
                }
            }
        }

        /// <summary>
        /// 用于Web 导出
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <param name="strFileName">文件名</param>

        public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName)
        {
            HttpContext context = HttpContext.Current;

            context.Response.ContentType = "application/vnd.ms-excel";
            context.Response.ContentEncoding = Encoding.UTF8;
            context.Response.Charset = "";
            context.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8));

            context.Response.BinaryWrite(Exprot(dtSource, strHeaderText).GetBuffer());
            context.Response.End();
        }

        /// <summary>
        /// 将泛型的list 集合导出Execl 
        /// </summary>
        /// <typeparam name="T">实体对象</typeparam>
        /// <param name="list">集合</param>
        /// <param name="strHeaderText">表头</param>
        /// <param name="strFileName">文件名字</param>
        public static void ExportToList<T>(List<T> list, string strHeaderText,string strFileName)
        {
            using (MemoryStream ms = ExprotToList<T>(list,strHeaderText))
            {
                using (FileStream fs = new FileStream(strFileName,FileMode.Create,FileAccess.Write))
                {
                    byte[] data = ms.ToArray();
                    fs.Write(data,0,data.Length);
                    fs.Flush();
                }
            }
        }

        /// <summary>
        /// DataTable导出到Excel的MemoryStream
        /// </summary>
        /// <param name="dt">数据源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <returns></returns>
        public static MemoryStream Exprot(DataTable dt, string strHeaderText)
        {
            HSSFWorkbook workBook = new HSSFWorkbook();

            ISheet sheet = workBook.CreateSheet();

            #region 右键属性
            {
                DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                dsi.Company = "NPOI";
                workBook.DocumentSummaryInformation =dsi;

                SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                si.Author = "文件作者信息";
                si.ApplicationName = "创建程序信息";
                si.LastAuthor = "最后保存者信息";
                si.Comments = "作者信息";
                si.Title = "标题信息";
                si.Subject = "主题信息";
                si.CreateDateTime = DateTime.Now;
                workBook.SummaryInformation = si;
            }
            #endregion

            ICellStyle dateStyle =  workBook.CreateCellStyle();
            IDataFormat dateFormat = workBook.CreateDataFormat();
            dateStyle.DataFormat = dateFormat.GetFormat("yyyy-MM-dd");

            //获取列宽
            int[] arrCollWidth = new int[dt.Columns.Count];

            foreach (DataColumn item in dt.Columns)
            {
                arrCollWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
            }

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    int intTemp = Encoding.GetEncoding(936).GetBytes(dt.Rows[i][j].ToString()).Length;

                    if (intTemp > arrCollWidth[j])
                    {
                        arrCollWidth[j] = intTemp;
                    }

                }
            }

            int rowIndex = 0;

            foreach (DataRow item in dt.Rows)
            {
                #region  新建表 填充表头 列头 样式
                {
                    if (rowIndex == 65535 || rowIndex == 0)
                    {
                        if (rowIndex != 0)
                        {
                            sheet = workBook.CreateSheet();
                        }

                        #region  表头及样式
                        {
                            IRow headerRow = sheet.CreateRow(0);
                            headerRow.HeightInPoints = 25;
                            headerRow.CreateCell(0).SetCellValue(strHeaderText); //填充填表

                            ICellStyle headerStyle = workBook.CreateCellStyle();
                            headerStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
                            IFont font = workBook.CreateFont();
                            font.FontHeightInPoints = 20;
                            font.Boldweight = 700;
                            headerStyle.SetFont(font);

                            headerRow.GetCell(0).CellStyle = headerStyle;
                            sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, dt.Columns.Count - 1));
                            // headerRow.Dispose();                            
                        }
                        #endregion

                        #region 列头及样式
                        {
                            IRow headRow = sheet.CreateRow(1);
                            ICellStyle headerStyle = workBook.CreateCellStyle();
                            headerStyle.Alignment =  NPOI.SS.UserModel.HorizontalAlignment.Center;
                            
                            IFont font = workBook.CreateFont();
                            font.FontHeightInPoints = 10;
                            font.Boldweight = 700;
                            headerStyle.SetFont(font);

                            foreach (DataColumn cl in dt.Columns)
                            {
                                headRow.CreateCell(cl.Ordinal).SetCellValue(cl.ColumnName);
                                headRow.GetCell(cl.Ordinal).CellStyle = headerStyle;

                                //设置列宽
                                sheet.SetColumnWidth(cl.Ordinal, (arrCollWidth[cl.Ordinal]+1)*256);
                            }
                        }
                        #endregion

                        rowIndex = 2;
                    }
                }
                #endregion


                #region 填充内容
                {
                       

                    IRow row = sheet.CreateRow(rowIndex);
                    foreach (DataColumn column in dt.Columns)
                    {
                        ICell cell = row.CreateCell(column.Ordinal);
                        
                        string drValue = item[column].ToString();

                        switch (column.DataType.ToString())
                        {
                            case "System.String":
                                cell.SetCellValue(drValue);
                                break;

                            case "System.DateTime":
                                DateTime dateV;
                                DateTime.TryParse(drValue, out dateV);
                                cell.SetCellValue(dateV);

                                cell.CellStyle = dateStyle;
                                break;

                            case "System.Boolean":
                                bool boolV;
                                bool.TryParse(drValue, out boolV);
                                cell.SetCellValue(boolV);
                                break;

                            case "System.Int16":
                            case "System.Int32":
                            case "System.Int64":
                            case "System.Byte":
                                int intV = 0;
                                int.TryParse(drValue, out intV);
                                cell.SetCellValue(intV);
                                break;

                            case "System.Decimal":
                            case "System.Double":
                                double doubleV = 0;
                                double.TryParse(drValue, out doubleV);
                                cell.SetCellValue(doubleV);
                                break;

                            case "System.DBNull":
                                cell.SetCellValue("");
                                break;
                            default:
                                cell.SetCellValue("");
                                break;
                        }
                    }


                }
                #endregion

                rowIndex++;
            }

            using (MemoryStream ms = new MemoryStream())
            {
                workBook.Write(ms);
                ms.Flush();
                ms.Position = 0;
                //sheet.Dispose();
                //workBook.Dispose();
                return ms;
            }

        }

        /// <summary>
        /// 将list 集合导处 Execl
        /// </summary>
        /// <param name="list">泛型集合</param>
        /// <param name="strHeaderName">表头名字</param>
        /// <returns></returns>
        public static MemoryStream ExprotToList<T>(List<T> list, string strHeaderName)
        {

            HSSFWorkbook workbook = new HSSFWorkbook();
            ISheet sheet = workbook.CreateSheet();            

            //创建样式

            ICellStyle cellStyle = workbook.CreateCellStyle();
            IDataFormat dataFormat = workbook.CreateDataFormat();
            cellStyle.DataFormat = dataFormat.GetFormat("yyyy-MM-dd");

            //IRow headerRow = sheet.CreateRow(0);
            //headerRow.CreateCell(0).SetCellValue(strHeaderName);

            //表头样式
            IRow headerRow = sheet.CreateRow(0);
            headerRow.HeightInPoints = 25;
            headerRow.CreateCell(0).SetCellValue(strHeaderName); //填充填表

            ICellStyle headerStyle = workbook.CreateCellStyle();
            headerStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
            IFont font = workbook.CreateFont();
            font.FontHeightInPoints = 20;
            font.Boldweight = 700;
            headerStyle.SetFont(font);

            headerRow.GetCell(0).CellStyle = headerStyle;
            sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, list[0].GetType().GetProperties().Length - 1));


            IRow rows = sheet.CreateRow(1);

            //获取list属性值
            PropertyInfo[] propertyInfo = list[0].GetType().GetProperties();

            #region 获取 实体 中的 [DisplayName("姓名")]
            {
                //获取 实体 中的 [DisplayName("姓名")]              

                Type entity = list[0].GetType();

                for (int i = 0; i < propertyInfo.Length; i++)
                {
                    var pName = entity.GetProperty(propertyInfo[i].Name.ToString()).GetCustomAttribute<DisplayNameAttribute>();

                    rows.CreateCell(i).SetCellValue(pName.DisplayName);
                }

                
            }
            #endregion           

            #region 获取实体的属性值  
            {             

                //for (int i = 0; i < propertyInfo.Length; i++)
                //{
                //    rows.CreateCell(i).SetCellValue(propertyInfo[i].Name.ToString());
                //}               
            }
            #endregion

            //填充内容
            int propertyIndex = 2;

            foreach (var item in list)
            {
                IRow row = sheet.CreateRow(propertyIndex);

                for (int i = 0; i < propertyInfo.Length; i++)
                {
                    var obj = propertyInfo[i].GetValue(item, null);

                    row.CreateCell(i).SetCellValue(obj.ToString());
                }

                propertyIndex++;
            }
           
            //宽度自适应
            for (int i = 0; i < list.Count; i++)
            {
                sheet.AutoSizeColumn(i);
            }

            using (MemoryStream ms = new MemoryStream())
            {
                workbook.Write(ms);
                ms.Flush();
                ms.Position = 0;
                return ms;
            }           
          

        }


        /// <summary>
        /// 读取Execl 表格
        /// </summary>
        /// <param name="fileName">文件路径</param>
        /// <returns></returns>
        public static DataTable GetReaderExecl(string fileName)
        {
            DataTable dt = new DataTable();

            HSSFWorkbook workBook;

            using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
            {
                workBook = new HSSFWorkbook(fs);
            }

            ISheet sheet = workBook.GetSheetAt(0);
            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

            IRow headerRow = sheet.GetRow(0);
            int cellCount = headerRow.LastCellNum;

            for (int i = 0; i < cellCount; i++)
            {
                ICell cell = headerRow.GetCell(i);
                dt.Columns.Add(cell.ToString());
            }

            for (int j = (sheet.FirstRowNum + 1); j <= sheet.LastRowNum; j++)
            {
                IRow row = sheet.GetRow(j);

                DataRow dr = dt.NewRow();

                for (int i = row.FirstCellNum; i <= cellCount; i++)
                {
                    if (row.GetCell(i) != null)
                    {
                        dr[i] = row.GetCell(i).ToString();
                    }
                }

                dt.Rows.Add(dr);
            }

            return dt;
        }

    }
}

解析一下 泛型集合导出Execl 中的一个问题

第一步：首先定义一个实体类

  public class People
    {
        [DisplayName("姓名")]
        public string name { get; set; }

        [DisplayName("年龄")]
        public string  Age { get; set; }

        [DisplayName("性别")]
        public string  Sex { get; set; }
    }

第二步：直接调用

 NPOIHelper.NPOIHelper.ExportToList<People>(this.GetLists(), "list","list.xls");

这样导出结果是这样的

表头显示的是 中文的 也就是实体类中的DisplayName 的值；如果不想使用这个值，想使用属性值得 也是可以的；将上面的代码 注释一下，将下面的 的代码解注一下 就OK 了

修改的代码如下：

 /// <summary>
        /// 将list 集合导处 Execl
        /// </summary>
        /// <param name="list">泛型集合</param>
        /// <param name="strHeaderName">表头名字</param>
        /// <returns></returns>
        public static MemoryStream ExprotToList<T>(List<T> list, string strHeaderName)
        {

            HSSFWorkbook workbook = new HSSFWorkbook();
            ISheet sheet = workbook.CreateSheet();            

            //创建样式

            ICellStyle cellStyle = workbook.CreateCellStyle();
            IDataFormat dataFormat = workbook.CreateDataFormat();
            cellStyle.DataFormat = dataFormat.GetFormat("yyyy-MM-dd");

            //IRow headerRow = sheet.CreateRow(0);
            //headerRow.CreateCell(0).SetCellValue(strHeaderName);

            //表头样式
            IRow headerRow = sheet.CreateRow(0);
            headerRow.HeightInPoints = 25;
            headerRow.CreateCell(0).SetCellValue(strHeaderName); //填充填表

            ICellStyle headerStyle = workbook.CreateCellStyle();
            headerStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
            IFont font = workbook.CreateFont();
            font.FontHeightInPoints = 20;
            font.Boldweight = 700;
            headerStyle.SetFont(font);

            headerRow.GetCell(0).CellStyle = headerStyle;
            sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, list[0].GetType().GetProperties().Length - 1));


            IRow rows = sheet.CreateRow(1);

            //获取list属性值
            PropertyInfo[] propertyInfo = list[0].GetType().GetProperties();

            #region 获取 实体 中的 [DisplayName("姓名")]
            {
                //获取 实体 中的 [DisplayName("姓名")]              

                //Type entity = list[0].GetType();

                //for (int i = 0; i < propertyInfo.Length; i++)
                //{
                //    var pName = entity.GetProperty(propertyInfo[i].Name.ToString()).GetCustomAttribute<DisplayNameAttribute>();

                //    rows.CreateCell(i).SetCellValue(pName.DisplayName);
                //}

                
            }
            #endregion           

            #region 获取实体的属性值  
            {

                for (int i = 0; i < propertyInfo.Length; i++)
                {
                    rows.CreateCell(i).SetCellValue(propertyInfo[i].Name.ToString());
                }               
            }
            #endregion

            //填充内容
            int propertyIndex = 2;

            foreach (var item in list)
            {
                IRow row = sheet.CreateRow(propertyIndex);

                for (int i = 0; i < propertyInfo.Length; i++)
                {
                    var obj = propertyInfo[i].GetValue(item, null);

                    row.CreateCell(i).SetCellValue(obj.ToString());
                }

                propertyIndex++;
            }
           
            //宽度自适应
            for (int i = 0; i < list.Count; i++)
            {
                sheet.AutoSizeColumn(i);
            }

            using (MemoryStream ms = new MemoryStream())
            {
                workbook.Write(ms);
                ms.Flush();
                ms.Position = 0;
                return ms;
            }           
          

        }

效果图：