将数据导出为Excel

一、创建一个类，将下面的代码(已封装好)写入
二、使用时直接调用
效果图


下面展示一些 内联代码片。
可以直接复制过去用，已封装好

 public class ExcelHelper
  {
 	/// <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();
            HSSFSheet sheet = workbook.CreateSheet("Sheet1");
	#region 右击文件 属性信息
	     {
                DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                dsi.Company = "";
                workbook.DocumentSummaryInformation = dsi;
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                si.Author = ""; //填加xls文件作者信息   
                si.ApplicationName = "NPOI测试程序"; //填加xls文件创建程序信息   
                si.LastAuthor = ""; //填加xls文件最后保存者信息   
                si.Comments = "说明信息"; //填加xls文件作者信息   
                si.Title = "NPOI测试"; //填加xls文件标题信息   
                si.Subject = "NPOI测试Demo";//填加文件主题信息   
                si.CreateDateTime = DateTime.Now;
                workbook.SummaryInformation = si;
              }
            #endregion
            HSSFCellStyle dateStyle = workbook.CreateCellStyle();
            HSSFDataFormat format = workbook.CreateDataFormat();
            dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");
//取得列宽   
            int[] arrColWidth = new int[dtSource.Columns.Count];
            foreach (DataColumn item in dtSource.Columns)
            {
                arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
            }
            for (int i = 0; i < dtSource.Rows.Count; i++)
            {
                for (int j = 0; j < dtSource.Columns.Count; j++)
                {
                int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
                    if (intTemp > arrColWidth[j])
                    {
                        arrColWidth[j] = intTemp;
                    }
                }
            }
	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
                    {
                        HSSFRow headerRow = sheet.CreateRow(0);
                        headerRow.HeightInPoints = 25;
                        headerRow.CreateCell(0).SetCellValue(strHeaderText);
HSSFCellStyle headStyle = workbook.CreateCellStyle();
                        // headStyle.Alignment = CellHorizontalAlignment.CENTER;
                        HSSFFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 20;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);
		headerRow.GetCell(0).CellStyle = headStyle;
		sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
  // headerRow.Dispose();
                    }
                    #endregion
	#region 列头及样式
                    {
                        HSSFRow headerRow = sheet.CreateRow(1);
                        HSSFCellStyle headStyle = workbook.CreateCellStyle();
                        // headStyle.Alignment = CellHorizontalAlignment.CENTER;
                        HSSFFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 10;
                        font.Boldweight = 700;
                        headStyle.SetFont(font);
                   foreach (DataColumn column in dtSource.Columns)
                     {
                           headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                          headerRow.GetCell(column.Ordinal).CellStyle = headStyle;
                          //设置列宽   
                            sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);
                             }
                        //   headerRow.Dispose();
                    }
                    #endregion
                     rowIndex = 2;
                }
                #endregion
              #region 填充内容
                HSSFRow dataRow = sheet.CreateRow(rowIndex);
                foreach (DataColumn column in dtSource.Columns)
                {
                    HSSFCell newCell = dataRow.CreateCell(column.Ordinal);
		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;
                            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":
                            double doubV = 0;
                            double.TryParse(drValue, out doubV);
                            newCell.SetCellValue(doubV);
                            break;
                            case "System.DBNull"://空值处理   
                            newCell.SetCellValue("");
                            break;
                        default:
                            newCell.SetCellValue("");
                            break;
                             }
                    #endregion
                         rowIndex++;
            }

	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);
            }
            HSSFSheet sheet = hssfworkbook.GetSheetAt(0);
            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
            HSSFRow headerRow = sheet.GetRow(0);
            int cellCount = headerRow.LastCellNum;
            for (int j = 0; j < cellCount; j++)
            {
                HSSFCell cell = headerRow.GetCell(j);
                dt.Columns.Add(cell.ToString());
            }
            for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
            {
            HSSFRow 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;
        }
     }

调用 注意格式

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本文地址：https://blog.csdn.net/d1332508051/article/details/107312421