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;
  }



 }
}

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