C#中使用NPOI将DataTable导出到Excel文件

NopiExcel.cs类

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data;
using NPOI.HSSF.UserModel;
using NPOI.HPSF;
using NPOI.SS.UserModel;
using System.Collections;
using System.Security.Cryptography;

namespace Common
{
public class NPOIExcel
{
/// <summary>
/// 将Excel读入到HashTable
/// </summary>
/// <param name="path">文件路径</param>
/// <returns>相应的DataTable</returns>
public static Hashtable ConvertToDataTable(string path)
{
if (path == "") return null;
HSSFWorkbook hssfworkbook=null;
try
{
using (FileStream file = new FileStream(path, FileMode.Open, FileAccess.Read))
{
hssfworkbook = new HSSFWorkbook(file);
}
}
catch
{
return null;
}

Hashtable ht = new Hashtable();
for (int e = 0; e < (int)hssfworkbook.Count; e++)
{
//获取excel的第一个sheet
ISheet sheet = hssfworkbook.GetSheetAt(e);
string sheetName = hssfworkbook.GetSheetName(e);
DataTable dt = new DataTable();
//获取sheet的首行
IRow headerRow = sheet.GetRow(0);

//一行最后一个方格的编号 即总的列数
int cellCount = headerRow.LastCellNum;

for (int i = headerRow.FirstCellNum; i < cellCount; i++)
{
DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
dt.Columns.Add(column);
}
//最后一列的标号  即总的行数
int rowCount = sheet.LastRowNum;

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();
else dataRow[j] = "";
}

dt.Rows.Add(dataRow);
}
sheet = null;
ht.Add(sheetName, dt);
}
hssfworkbook = null;
return ht;
}

/// <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(Hashtable ht, string strFileName)
{
HSSFWorkbook workbook = new HSSFWorkbook();

foreach (DictionaryEntry de in ht)
{
DataTable dt = (DataTable)de.Value;
string sheetName = (string)de.Key;
ISheet sheet = workbook.CreateSheet(sheetName);
IRow dataRow = sheet.CreateRow(0);
foreach (DataColumn column in dt.Columns)
{
dataRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
}

//填充内容
for (int i = 0; i < dt.Rows.Count; i++)
{
dataRow = sheet.CreateRow(i + 1);
for (int j = 0; j < dt.Columns.Count; j++)
{
dataRow.CreateCell(j).SetCellValue(dt.Rows[i][j].ToString());
}
}
}
workbook.Write(new FileStream(strFileName, FileMode.Create, FileAccess.Write));
}
}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Business;
using Common;//nopiExcel放在namespace Commom下
using System.Collections;
using System.Data;
namespace CourseCaculate.PrimaryC
{
public partial class PrimaryCExport : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{

}
}

/// <summary>
/// 导出
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public void btnExport_Click(object sender, EventArgs e)
{

DataTable dt = CourseMarksDAL.GetDataTableLike();

IList<string> toEraseList = new List<string>();
for (int i = 0; i < dt.Columns.Count; i++)
{
if (!InNameList(dt.Columns[i].ColumnName))
{
//dt.Columns.RemoveAt(i);
toEraseList.Add(dt.Columns[i].ColumnName);
}
}
foreach (string s in toEraseList)
{
dt.Columns.Remove(s);
}
dt.Columns["TicketNum"].ColumnName = "准考证号";
dt.Columns["StuID"].ColumnName = "学号";
dt.Columns["StuName"].ColumnName = "姓名";
dt.Columns["ProfeName"].ColumnName = "专业名称";
dt.Columns["ExamMarks"].ColumnName = "笔试成绩";

string fileName = "C语言成绩.xls";
NPOIHelper.ExportByWeb(dt, fileName);
}

/// <summary>
/// 判断是否为列名
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public bool InNameList(string name)
{
string[] nameList = { "TicketNum", "StuID", "StuName", "ProfeName", "ExamMarks"};
for (int i = 0; i < (int)nameList.Length; i++)
{
if (name == nameList[i])
{
return true;
}
}
return false;
}

}
}