分享一个前辈的NPOIhelper

即拿即用:

首先要下载npoi的dll,此不赘述,接着添加引用:

using NPOI.HPSF;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.SS.Util;

下面是主要方法

public class NPOIHelper
    {
        /// <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 DataTableToExcel(DataTable dtSource, string strHeaderText, string strFileName)
         {
             using (MemoryStream ms = DataTableToExcel(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 DataTableToExcel(DataTable dtSource, string strHeaderText)
         {
             HSSFWorkbook workbook = new HSSFWorkbook();
             HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet();
 
             #region 右击文件 属性信息
             {
                 DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                 dsi.Company = "NPOI";
                 workbook.DocumentSummaryInformation = dsi;
 
                 SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                 si.Author = "文件作者信息"; //填加xls文件作者信息
                 si.ApplicationName = "创建程序信息"; //填加xls文件创建程序信息
                 si.LastAuthor = "最后保存者信息"; //填加xls文件最后保存者信息
                 si.Comments = "作者信息"; //填加xls文件作者信息
                 si.Title = "标题信息"; //填加xls文件标题信息
                 si.Subject = "主题信息";//填加文件主题信息
                 si.CreateDateTime = System.DateTime.Now;
                 workbook.SummaryInformation = si;
             }
             #endregion

             HSSFCellStyle dateStyle = (HSSFCellStyle)workbook.CreateCellStyle();
             HSSFDataFormat format = (HSSFDataFormat)workbook.CreateDataFormat();
             dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");
             //边框
             dateStyle.BorderBottom = BorderStyle.Thin;
             dateStyle.BorderLeft = BorderStyle.Thin;
             dateStyle.BorderRight = BorderStyle.Thin;
             dateStyle.BorderTop = BorderStyle.Thin;

             //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 = (HSSFSheet)workbook.CreateSheet();
                     }
 
                     #region 表头及样式
                     {
                         HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
                         headerRow.HeightInPoints = 25;
                         headerRow.CreateCell(0).SetCellValue(strHeaderText);

                         HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
                         headStyle.Alignment = HorizontalAlignment.Center;


                         HSSFFont font = (HSSFFont)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));
                                               
                     }
                     #endregion
 
 
                     #region 列头及样式
                     {
                         HSSFRow headerRow = (HSSFRow)sheet.CreateRow(1); 
                         HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
                         headStyle.Alignment = HorizontalAlignment.Center;

                         //边框
                         headStyle.BorderBottom = BorderStyle.Thin;
                         headStyle.BorderLeft = BorderStyle.Thin;
                         headStyle.BorderRight = BorderStyle.Thin;
                         headStyle.BorderTop = BorderStyle.Thin;

                         HSSFFont font = (HSSFFont)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 = (HSSFRow)sheet.CreateRow(rowIndex);

                 #region 边框,样式

                 HSSFCellStyle NewCellStyle = (HSSFCellStyle)workbook.CreateCellStyle();
                 NewCellStyle.Alignment = HorizontalAlignment.Center;

                 //边框
                 NewCellStyle.BorderBottom = BorderStyle.Thin;
                 NewCellStyle.BorderLeft = BorderStyle.Thin;
                 NewCellStyle.BorderRight = BorderStyle.Thin;
                 NewCellStyle.BorderTop = BorderStyle.Thin;
                 #endregion

                 foreach (DataColumn column in dtSource.Columns)
                 {
                     HSSFCell newCell =(HSSFCell) dataRow.CreateCell(column.Ordinal);

                    
                     string drValue = row[column].ToString();
 
                     switch (column.DataType.ToString())
                     {
                         case "System.String"://字符串类型
                             newCell.SetCellValue(drValue);
                             newCell.CellStyle = NewCellStyle;
                             break;
                         case "System.DateTime"://日期类型
                            System.DateTime dateV;
                            System.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);
                             newCell.CellStyle = NewCellStyle;
                             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);
                             newCell.CellStyle = NewCellStyle;
                             break;
                         case "System.Decimal"://浮点型
                         case "System.Double":
                             double doubV = 0;
                             double.TryParse(drValue, out doubV);
                             newCell.SetCellValue(doubV);
                             newCell.CellStyle = NewCellStyle;
                             break;
                         case "System.DBNull"://空值处理
                             newCell.SetCellValue("");
                             newCell.CellStyle = NewCellStyle;
                             break;
                         default:
                             newCell.SetCellValue("");
                             newCell.CellStyle = NewCellStyle;
                             break;
                     }
 
                 }
                 #endregion
 
                 rowIndex++;
             } 
             using (MemoryStream ms = new MemoryStream())
             {
                 workbook.Write(ms);
                 ms.Flush();
                 ms.Position = 0;                                 
                 return ms;
             } 
         }
    }

 后面调用这个类,如下:

string dir = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);//取得当前桌面路径

 NPOIHelper.DataTableToExcel(dt,"文档测试",dir+@"测试.xls");