C# MVC实现导出到EXCEL

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u012571917/article/details/78186674

这是ExcelHelper文件

using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Web;
using NPOI;
using NPOI.HPSF;
using NPOI.HSSF;
using NPOI.HSSF.UserModel;
using NPOI.HSSF.Util;
using NPOI.POIFS;
using NPOI.SS.UserModel;
using NPOI.Util;

namespace EENT.App.SED.Web.Helpers
{
    public class ExcelHelper
    {
        /// <summary>
        /// DataTable导出到Excel文件
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        /// <param name="strFileName">保存位置</param>
        public static void Export(DataTable dtSource, string strHeaderText, string strFileName)
        {
            using(MemoryStream ms = Export(dtSource, 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="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表头文本</param>
        public static MemoryStream Export(DataTable dtSource, string strHeaderText)
        {
            HSSFWorkbook workbook = new HSSFWorkbook();
            ISheet sheet = workbook.CreateSheet();

            IDataFormat format = workbook.CreateDataFormat();
            ICellStyle dateStyle = workbook.CreateCellStyle();
            dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");
            ICellStyle decimalStyle = workbook.CreateCellStyle();
            decimalStyle.DataFormat = format.GetFormat("N2");

            List<int> theExportCols     = new List<int>();

            int rowIndex = 0;

            foreach(DataRow row in dtSource.Rows)
            {
                #region 新建表，填充表头，填充列头，样式

                if(rowIndex == 65535 || rowIndex == 0)
                {
                    if(rowIndex != 0)
                    {
                        sheet = workbook.CreateSheet();
                    }

                    #region 表头及样式

                    if(!String.IsNullOrEmpty(strHeaderText))
                    {
                        IRow headerRow = sheet.CreateRow(rowIndex);
                        headerRow.HeightInPoints = 25;
                        headerRow.CreateCell(0).SetCellValue(strHeaderText);

                        ICellStyle headStyle = workbook.CreateCellStyle();
                        headStyle.Alignment = HorizontalAlignment.Center;
                        IFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 20;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);

                        headerRow.GetCell(0).CellStyle = headStyle;

                        //sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, dtSource.Columns.Count - 1));
                        //headerRow.Dispose();

                        rowIndex++;
                    }

                    #endregion 表头及样式


                    #region 列头及样式

                    {
                        IRow headerRow = sheet.CreateRow(rowIndex);


                        ICellStyle headStyle = workbook.CreateCellStyle();
                        headStyle.Alignment = HorizontalAlignment.Center;
                        IFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 10;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);

                        foreach(DataColumn column in dtSource.Columns)
                        {
                            if(!String.IsNullOrEmpty(column.Caption))
                            {
                                ICell cell  = headerRow.CreateCell(theExportCols.Count);
                                cell.SetCellValue(column.Caption);
                                cell.CellStyle = headStyle;
                                theExportCols.Add(column.Ordinal);
                            }
                            //else
                            //{
                            //    headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                            //}
                        }
                        //headerRow.Dispose();
                        rowIndex++;
                    }

                    #endregion 列头及样式
                }

                #endregion 新建表，填充表头，填充列头，样式


                #region 填充内容

                IRow dataRow = sheet.CreateRow(rowIndex);
                for(int i = 0; i < theExportCols.Count; i++)
                {
                    var column  = dtSource.Columns[theExportCols[i]];
                //}
                //foreach(DataColumn column in dtSource.Columns)
                //{
                    ICell newCell = dataRow.CreateCell(i);

                    string drValue = row[column].ToString();

                    switch(column.DataType.ToString())
                    {
                        case "System.String"://字符串类型
                            newCell.SetCellValue(drValue);
                            break;
                        case "System.DateTime"://日期类型
                            DateTime dateV;
                            if(DateTime.TryParse(drValue, out dateV))
                            {
                                newCell.SetCellValue(dateV);
                                newCell.CellStyle = dateStyle;//格式化显示
                            }
                            break;
                        case "System.Boolean"://布尔型
                            bool boolV = false;
                            bool.TryParse(drValue, out boolV);
                            newCell.SetCellValue(boolV);
                            break;
                        case "System.Int16"://整型
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            int intV = 0;
                            int.TryParse(drValue, out intV);
                            newCell.SetCellValue(intV);
                            break;
                        case "System.Decimal"://浮点型
                        case "System.Double":
                        case "System.Single":
                            double doubV = 0;
                            double.TryParse(drValue, out doubV);
                            newCell.SetCellValue(doubV);
                            newCell.CellStyle = decimalStyle;
                            break;
                        case "System.DBNull"://空值处理
                            newCell.SetCellValue("");
                            break;
                        default:
                            newCell.SetCellValue("");
                            break;
                    }
                }

                #endregion 填充内容

                rowIndex++;
            }

            for(int i = 0; i < theExportCols.Count; i++)
            {
                sheet.AutoSizeColumn(i, true);
            }

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

                //sheet.Dispose();
                //workbook.Dispose();//一般只用写这一个就OK了，他会遍历并释放所有资源，但当前版本有问题所以只释放sheet
                return ms;
            }
        }


        /// <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 curContext = HttpContext.Current;

            // 设置编码和附件格式
            curContext.Response.ContentType = "application/vnd.ms-excel";
            curContext.Response.ContentEncoding = Encoding.UTF8;
            curContext.Response.Charset = "";
            curContext.Response.AppendHeader("Content-Disposition",
                "attachment;filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8));

            curContext.Response.BinaryWrite(Export(dtSource, strHeaderText).GetBuffer());
            curContext.Response.End();
        }


        /// <summary>读取excel
        /// 默认第一行为标头
        /// </summary>
        /// <param name="strFileName">excel文档路径</param>
        /// <returns></returns>
        public static DataTable Import(string strFileName)
        {
            DataTable dt = new DataTable();

            HSSFWorkbook hssfworkbook;
            using(FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
            {
                hssfworkbook = new HSSFWorkbook(file);
            }
            ISheet sheet = hssfworkbook.GetSheetAt(0);
            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

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

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

            for(int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
            {
                IRow row = sheet.GetRow(i);
                DataRow dataRow = dt.NewRow();

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

                dt.Rows.Add(dataRow);
            }
            return dt;
        }
    }
}

这是 Controller里边的方法

  public void ExportToExcel()
        {

            var data = projectDS.GetProjectMessage(11);
            DataTable dtData = new DataTable();
            dtData.Columns.Add("项目名称", typeof(string));
            dtData.Columns.Add("负责人", typeof(string));
            dtData.Columns.Add("病例数", typeof(string));
            dtData.Columns.Add("表单数", typeof(string));
            dtData.Columns.Add("开始日期", typeof(string));
            for (int i = 0; i < data.Rows.Count; i++)
            {
                DataRow newrow = dtData.NewRow();
                newrow["项目名称"] = data.Rows[i].ItemArray[0];
                newrow["负责人"] = data.Rows[i].ItemArray[1];
                newrow["病例数"] = data.Rows[i].ItemArray[3];
                newrow["表单数"] = data.Rows[i].ItemArray[4];
                newrow["开始日期"] = data.Rows[i].ItemArray[2];
                dtData.Rows.Add(newrow);
            }
            ExcelHelper.ExportByWeb(dtData, String.Empty, "经费来源单位统计.xls");

        }

前台html页面的调用

 <a class="btn blue" href="/ProjectSupervisionUnit/ExportToExcel">导出到Excel</a>