使用npoi做excel导出真心方便

using System;
using System.Data;
using System.IO;
using System.Web;
using NPOI.HPSF;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.SS.Util;

///作者：sj178220709/// <summary>
/// 构造函数初始化的时候，确定excel的模板
/// 在外部准备好每行的信息 循环调用BindRowData
/// cs和bs分别调用对应的下载方法
/// Ps：默认添加了“序号”列 ，样式也是默认的
///
/// </summary>
public class NpoiHelper
{
private readonly HSSFWorkbook _workbook;
private readonly ISheet _sheet1;
//private ICellStyle _titleStyle;
private readonly string[] _params;

public HSSFWorkbook Workbook
{
get { return _workbook; }
}
/// <summary>
/// 构造函数
/// </summary>

/// <param name="title">合同和sheet的标题</param>
/// <param name="colInfos">[注意，序号会自动生成]params列名参数，数目即列数</param>
public NpoiHelper( string title, params  string[] colInfos)
{
this._workbook = new HSSFWorkbook();
this._sheet1 = this.Workbook.CreateSheet(title);
this._params = colInfos;
this.SetFileInfo();
this.SetTitleRow(title, colInfos.Length);
this.SetSecondRow(_params);
}

/// <summary>
/// 绑定数据,可直接从数据库中取出数据时使用，
/// </summary>
/// <param name="dt">只包含需要数据的datatable</param>
/// <param name="colNames">字段在数据库中的列名</param>
public  void BindTableData(DataTable dt,params  string[] colNames)
{

ICellStyle cellStyle = this.Workbook.CreateCellStyle();
cellStyle.Alignment = HorizontalAlignment.CENTER;
cellStyle.BorderBottom = BorderStyle.THIN;
cellStyle.BorderTop = BorderStyle.THIN;
cellStyle.BorderLeft = BorderStyle.THIN;
cellStyle.BorderRight = BorderStyle.THIN;

int i = 2;  //注意内容的行数并不是从第一行开始的
int colCount = this._params.Length;

//先遍历dt 取出行数（dr数目），每行第一列添加一个序号的表头，再遍历表头信息数组填充数据
foreach (DataRow dr in dt.Rows)
{
IRow row = this._sheet1.CreateRow(i);
ICell cell0 = row.CreateCell(0);
cell0.CellStyle = cellStyle;
cell0.SetCellValue(i-1);//设置序号
for (int j = 0; j < colCount; j++)
{
ICell cell = row.CreateCell(j+1);
cell.CellStyle = cellStyle;
cell.SetCellValue(dr[colNames[j]].ToString());
}
i++;
}
}

/// <summary>
/// 【注意起始行的位置】在外部绑定每一行的数据
/// </summary>
/// <param name="rowIndex">当前行数,正文从第3行(index=2)开始</param>
/// <param name="colValues">每列的数据，请按前面构造函数输入的列信息依次输入</param>
public void BindRowData(int rowIndex, params string[] colValues)
{
ICellStyle cellStyle = this.Workbook.CreateCellStyle();
cellStyle.Alignment = HorizontalAlignment.CENTER;
cellStyle.BorderBottom = BorderStyle.THIN;
cellStyle.BorderTop = BorderStyle.THIN;
cellStyle.BorderLeft = BorderStyle.THIN;
cellStyle.BorderRight = BorderStyle.THIN;

int colCount = this._params.Length;

//先遍历dt 取出行数（dr数目），每行第一列添加一个序号的表头，再遍历表头信息数组填充数据

IRow row = this._sheet1.CreateRow(rowIndex);
ICell cell0 = row.CreateCell(0);
cell0.CellStyle = cellStyle;
cell0.SetCellValue(rowIndex - 1); //设置序号
for (int j = 0; j < colCount; j++)
{
ICell cell = row.CreateCell(j + 1);
cell.CellStyle = cellStyle;
cell.SetCellValue(colValues[j]);
}
}

/// <summary>
/// 设置Workbook的2个属性信息
/// </summary>
private void SetFileInfo()
{
//设置Workbook的DocumentSummaryInformation信息
DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = "CHMTECH";
this.Workbook.DocumentSummaryInformation = dsi;

//设置Workbook的SummaryInformation信息
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
si.Subject = "CHMTECH EXCEL-EXPORT";
this.Workbook.SummaryInformation = si;
}

/// <summary>
/// 设置第一行为title行 里面的一些样式直接写死了
/// </summary>
/// <param name="titleStr">第一行title的context</param>
/// <param name="mergedCount">合并的列数，一般为列头信息个数</param>
/// <returns></returns>
private void SetTitleRow(string titleStr, int mergedCount)
{
IRow titleRow = this._sheet1.CreateRow(0);
titleRow.Height = 30 * 20;
ICellStyle titleStyle = this.Workbook.CreateCellStyle();
titleStyle.Alignment = HorizontalAlignment.CENTER; //字体排列

//合并titleRow的格子 因为多了个序号，所以合并的时候也需要多合并一格
this._sheet1.AddMergedRegion(new CellRangeAddress(0, 0, 0, mergedCount ));

IFont font = this.Workbook.CreateFont(); //set font style
font.FontHeight = 40 * 20;
font.Boldweight = (short)FontBoldWeight.BOLD; //bold
font.FontHeightInPoints = 16; //字体大小
titleStyle.SetFont(font);
ICell titleCell = titleRow.CreateCell(0);
titleCell.SetCellValue(new HSSFRichTextString(titleStr)); //title context
titleCell.CellStyle = titleStyle; //bind style

}

//设置第二行的列头信息，注意序号带来的index+1问题
private void SetSecondRow(string[] headArr)
{

ICellStyle style = this.Workbook.CreateCellStyle();
style.Alignment = HorizontalAlignment.CENTER;
style.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.LIGHT_YELLOW.index;
style.FillPattern = FillPatternType.SOLID_FOREGROUND;

IRow irow = this._sheet1.CreateRow(1);
//序号格子
HSSFCell indexCell = (HSSFCell)irow.CreateCell(0);
indexCell.SetCellValue("序号");
this._sheet1.SetColumnWidth(0, 5 * 256);

irow.Height = 20 * 20;
for (int i = 0; i < headArr.Length; i++)
{
string cellValue = headArr[i];
HSSFCell curCell = (HSSFCell)irow.CreateCell(i+1);
curCell.SetCellValue(cellValue);
this._sheet1.SetColumnWidth(i+1, 20 * 256);
curCell.CellStyle = style;
}
}

//public void GetOutPutStream(ref Stream stream)
//{
//   this.Workbook.Write(stream);
//}

/// <summary>
/// 打印xls文件
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
public  bool PrintXls( string path)
{
try
{
FileStream fs = File.Create(path);
this.Workbook.Write(fs);
fs.Flush();
fs.Close();
return true;
}
catch (Exception)
{
return false;
}
}

/// <summary>
/// 提供下载，通过response输出2进制信息。
/// </summary>
/// <param name="Response">当前页面的response</param>
/// <param name="fileName">文件名，无须输入后缀名</param>
public void OutPutDownload(HttpResponse Response,string fileName)
{
//导出，让用户下载

if (!fileName.EndsWith(@".xls"))
{
fileName += @".xls";
}
Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileName));
Response.AddHeader("Content-Transfer-Encoding", "binary");
Response.ContentType = "application/vnd.ms-excel";
Response.ContentEncoding = System.Text.Encoding.GetEncoding("UTF-8");
Response.Clear();
MemoryStream file = new MemoryStream();
this.Workbook.Write(file);
Response.BinaryWrite(file.GetBuffer());
Response.End();
}

}