NPOI导出excel（带图片）

近期项目中用到Excel导出功能，之前都是用普通的office组件导出的方法，今天尝试用下NPOI，故作此文以备日后查阅。

1.NPOI官网http://npoi.codeplex.com/，下载最新工具包。

2.选择.net版本（例如dotnet4），引用其中的dll。

3.后台代码

using System;
using System.Web;
using System.Data;
using System.Configuration;
using System.IO;
using Test_DBUtility;
using NPOI;
using NPOI.SS.UserModel;
using NPOI.HSSF.UserModel;

public partial class Handlers_ExportExcel : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string act = Request["action"].ToString();
            DataTable dt = new DataTable();
            string sql = string.Empty;
            int[] array = new int[] { };
            switch (act)
            {
                case "export":
                    sql = @"select M_MEDIUM 产品图片,PN,CN_NAME 产品名称,EN_NAME 英文名称,DESC_CN 中文描述,DESC_EN 英文描述,REMARKS 备注描述,MANUFACTURER_PN 厂家编码,PROVIDER_FULL_NAME 供应商,SP_RESULT 审批结果," +
                           "RANK 产品定级,BASE_STOCK 基础库存,COST 实际成本,CURRENT_PRICE 现价,SPECIAL_PRICE 特价 from viewsdb_en.dbo.View_ProductExcelExport";
                    dt = SqlHelper.Query(sql).Tables[0];
                    array = new int[] { 20, 15, 20, 20, 80, 80, 80, 20, 40, 10, 10, 10, 12, 12, 12 }; //定义列宽
                    NpoiExcel(dt, "操作表", array);
                    break;
            }
        }
    }

    /// <summary>
    /// NPOI导出EXCEL
    /// </summary>
    /// <param name="dt">数据源</param>
    /// <param name="title">导出文件的名称</param>
    /// <param name="array">列宽数组</param>
    public void NpoiExcel(DataTable dt, string title, int[] array)
    {
        NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
        NPOI.SS.UserModel.ISheet sheet = book.CreateSheet("Sheet1");

        NPOI.SS.UserModel.IRow headerrow = sheet.CreateRow(0);
        headerrow.Height = 30 * 20;
        ICellStyle style = book.CreateCellStyle();
        style.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;
        style.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;
        style.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;
        style.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;
        style.WrapText = true;
        style.Alignment = HorizontalAlignment.Center;
        style.VerticalAlignment = VerticalAlignment.Center;

        /*标题*/
        for (int i = 0; i < dt.Columns.Count; i++)
        {
            ICell cell = headerrow.CreateCell(i);
            cell.CellStyle = style;
            cell.SetCellValue(dt.Columns[i].ColumnName);
            /*设置列宽*/
            if (array.Length > 0)
            {
                for (int c = 0; c < array.Length; c++)
                {
                    sheet.SetColumnWidth(c, array[c] * 256);
                }
            }
        }

        /*内容*/
        for (int j = 1; j <= dt.Rows.Count; j++)
        {
            NPOI.SS.UserModel.IRow contentrow = sheet.CreateRow(j);
            contentrow.Height = 100 * 20;
            for (int k = 0; k < dt.Columns.Count; k++)
            {
                ICell cell = contentrow.CreateCell(k);
                cell.CellStyle = style;
                if (k == 0)
                {
                    string picurl = dt.Rows[j - 1][k].ToString();
                    AddCellPicture(sheet, book, picurl, j, k);
                }
                else
                {
                    cell.CellStyle = style;
                    cell.SetCellValue(dt.Rows[j - 1][k].ToString());
                }
            }
        }

        MemoryStream ms = new MemoryStream();
        book.Write(ms);
        Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", HttpUtility.UrlEncode(title + "_" + DateTime.Now.ToString("yyyy-MM-dd"), System.Text.Encoding.UTF8)));
        Response.BinaryWrite(ms.ToArray());
        Response.End();
        book = null;
        ms.Close();
        ms.Dispose();
    }

    /// <summary>
    /// 向sheet插入图片
    /// </summary>
    /// <param name="sheet"></param>
    /// <param name="workbook"></param>
    /// <param name="fileurl"></param>
    /// <param name="row"></param>
    /// <param name="col"></param>
    private void AddCellPicture(ISheet sheet, HSSFWorkbook workbook, string fileurl, int row, int col)
    {
        try
        {
            //由于File类只能读取本地资源，所以在配置文件中配置了物理路径的前半部分
            string DiscPath = ConfigurationManager.AppSettings["PictureDiscPath"];
            string FileName = DiscPath.Replace("\\", "/") + fileurl.Replace("http://www.bolioptics.com/", "");
            if (File.Exists(FileName) == true)
            {
                byte[] bytes = System.IO.File.ReadAllBytes(FileName);
                if (!string.IsNullOrEmpty(FileName))
                {
                    int pictureIdx = workbook.AddPicture(bytes, NPOI.SS.UserModel.PictureType.JPEG);
                    HSSFPatriarch patriarch = (HSSFPatriarch)sheet.CreateDrawingPatriarch();
                    HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 0, 0, col, row, col + 1, row + 1);
                    HSSFPicture pict = (HSSFPicture)patriarch.CreatePicture(anchor, pictureIdx);
                }
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
}