C#使用Datatable导出Excel

本文实例为大家分享了C#使用Datatable导出Excel的具体代码，供大家参考，具体内容如下

using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using Newtonsoft.Json;
namespace EasyFrame.Common
{
/// <summary>
///title调用信息
/// </summary>
public class ChartTitle
{
 /// <summary>
 /// 调用名
 /// </summary>
 public string CallName { get; set; }
 /// <summary>
 /// 标头信息
 /// </summary>
 public List<ChartName> SetNameList { get; set; }
}
public class ChartName
{
 /// <summary>
 /// 一级标头
 /// </summary>
 public string Name { get; set; }
 /// <summary>
 /// 二级标头
 /// </summary>
 public List<string> ChartChildNameList { get; set; }

}

public class ExcelHelper
{

//
 /// <summary>
 /// Datatable导出Excel
 /// </summary>
 /// <param name="dt">数据</param>
 /// <param name="list">表头</param>
 /// <param name="counts">总条数</param>
 /// <param name="filePath">保存地址</param>
 /// <returns></returns>
 public static MemoryStream WriteExcel(DataTable dt, List<ChartTitle> objlist, string filePath)
 {
  var list = objlist.FirstOrDefault(a => a.CallName == "ccc").SetNameList;
  if (!string.IsNullOrEmpty(filePath) && null != dt && dt.Rows.Count > 0)
  {
   XSSFWorkbook book = new XSSFWorkbook();
   NPOI.SS.UserModel.ISheet sheet = book.CreateSheet(dt.TableName);
   ICell cell = null;
   ICellStyle style = book.CreateCellStyle();
   IFont font = book.CreateFont();//创建字体样式
   IFont fonts = book.CreateFont();//创建字体样式
   IFont fontss = book.CreateFont();//创建字体样式
   font.Color = NPOI.HSSF.Util.HSSFColor.Red.Index;//设置字体颜色
   ICellStyle styles = book.CreateCellStyle(); //红色
   fonts.Color = NPOI.HSSF.Util.HSSFColor.Green.Index;
   ICellStyle styless = book.CreateCellStyle(); //绿色
   fontss.Color = NPOI.HSSF.Util.HSSFColor.Blue.Index;
   ICellStyle stylesss = book.CreateCellStyle(); //蓝色
   styless.SetFont(fonts);
   styles.SetFont(font);
   stylesss.SetFont(fontss);
   style.Alignment = HorizontalAlignment.Center;
   NPOI.SS.UserModel.IRow row1 = sheet.CreateRow(0);
   NPOI.SS.UserModel.IRow row2 = sheet.CreateRow(1);
   var row = row1;
   int num = 0;//记录列
   var d = true;//是否第一次加载到二级表单
   #region 创建表头
   //两行单列
   for (int i = 0; i < list.Count; i++)
   {
    if (!d)
    {
     row = row1;
     d = true;
    }
    if (list[i].ChartChildNameList == null)
    {
     cell = row.CreateCell(num);
     sheet.SetColumnWidth(num, 15 * 256);
     cell.SetCellValue(list[i].Name);
     cell.CellStyle = style;
     sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 1, num, num));
     num++;
     continue;
    }
    //两行多列
    var count = list[i].ChartChildNameList.Count; //列数
    cell = row.CreateCell(num);
    cell.SetCellValue(list[i].Name);
    cell.CellStyle = style;
    sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, num, count + num - 1));
    if (d)
    {
     d = false;
     row = row2;
    }
    var t = 0;
    var rang = sheet.GetRow(1);
    for (int j = 0; j < count; j++)
    {
     sheet.SetColumnWidth(num + t, 5 * 256);
     cell = row.CreateCell(num + t);
     cell.SetCellValue(list[i].ChartChildNameList[j]);
     cell.CellStyle = style;
     t++;
    }
    num = num + count;
   }
   #endregion 创建表头
   #region 写入数据
   int customs = 0;//记录列数
   int clouns = 0;//记录行数

filePath = string.Format(filePath, "XXX");
   #region 导出操作
   var data1 = JsonConvert.DeserializeObject<List<类名>>(dt.Rows[0][0].ToString());
   foreach (var item in data1)
   {
    NPOI.SS.UserModel.IRow rows = sheet.CreateRow(clouns + 2);
    customs = 0;
    rows.CreateCell(customs).SetCellValue(Convert.ToString(item.No)); customs++;
    rows.CreateCell(customs).SetCellValue(Convert.ToString(item.LotteryOpenNo)); customs++;
    for (int i = 0; i < item.Wan.Length; i++)
    {
     if (item.LotteryOpenNo.Split(',')[0] == item.Wan[i].ToString())
     {
      cell = rows.CreateCell(customs);
      cell.SetCellValue(item.Wan[i]);
      cell.CellStyle = styles;
      customs++;
     }
     else
     {
      rows.CreateCell(customs).SetCellValue(item.Wan[i]); customs++;
     }
    }
    for (int j = 0; j < item.Qian.Length; j++)
    {
     if (item.LotteryOpenNo.Split(',')[1] == item.Qian[j].ToString())
     {
      cell = rows.CreateCell(customs);
      cell.SetCellValue(item.Qian[j]);
      cell.CellStyle = styles;
      customs++;
     }
     else
     {
      rows.CreateCell(customs).SetCellValue(item.Qian[j]); customs++;
     }
    }
    for (int k = 0; k < item.Bai.Length; k++)
    {
     if (item.LotteryOpenNo.Split(',')[2] == item.Bai[k].ToString())
     {
      cell = rows.CreateCell(customs);
      cell.SetCellValue(item.Bai[k]);
      cell.CellStyle = styles;
      customs++;
     }
     else
     {
      rows.CreateCell(customs).SetCellValue(item.Bai[k]); customs++;
     }
    }
    for (int l = 0; l < item.Shi.Length; l++)
    {
     if (item.LotteryOpenNo.Split(',')[3] == (item.Shi[l].ToString()))
     {
      cell = rows.CreateCell(customs);
      cell.SetCellValue(item.Shi[l]);
      cell.CellStyle = styles;
      customs++;
     }
     else
     {
      rows.CreateCell(customs).SetCellValue(item.Shi[l]); customs++;
     }
    }
    for (int m = 0; m < item.Ge.Length; m++)
    {
     if (item.LotteryOpenNo.Split(',')[4] == (item.Ge[m].ToString()))
     {
      cell = rows.CreateCell(customs);
      cell.SetCellValue(item.Ge[m]);
      cell.CellStyle = styles;
      customs++;
     }
     else
     {
      rows.CreateCell(customs).SetCellValue(item.Ge[m]); customs++;
     }
    }
    for (int n = 0; n < item.Fen.Length; n++)
    {
     if (item.LotteryOpenNo.Contains(item.Fen[n].ToString()))
     {
      cell = rows.CreateCell(customs);
      cell.SetCellValue(item.Fen[n]);
      cell.CellStyle = styles;
      customs++;
     }
     else
     {
      rows.CreateCell(customs).SetCellValue(item.Fen[n]); customs++;
     }

}
    clouns++;
   }

#endregion

#endregion 写入数据
   // 写入到客户端
   using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
   {
    book.Write(ms);
    using (FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.Write))
    {
     byte[] data = ms.ToArray();
     fs.Write(data, 0, data.Length);
     fs.Flush();
    }
    book = null;
    return ms;
   }
  }
  return null;
 }

}
}

来源：https://www.cnblogs.com/yuanzijian-ruiec/archive/2018/10/01/9734280.html