NPOI復制模板導出Excel

本人菜鳥實習生一枚，公司給我安排了一個excel導出功能。要求如下：1、導出excel文件有樣式要求；2、導出excel包含一個或多個工作表；3、功能做活（我的理解就是excel樣式以后可能會變方便維護修改）；如何圖所示是公司提供的excel模板

導出excel的功能之前在學校做過，我的第一個想到的是使用Microsoft.Office.Interop.Excel.dll讀取Excel文件，但是公司的電腦上沒有安裝office沒有相應的組件，我只能換種方法查了資料最后決定使用NPOI。用什么的問題解決了后面該想想怎么做了，當時想自己用代碼寫樣式不過盯着模板看了一會后想想自己寫不現實而且不便於后期維護（其實就是會寫）。於是換種思路通過復制模板生產中間excel進行導出即使以后樣式要修改也可以通過修改模板來實現盡量不去動代碼。下面是代碼

 /// <summary>
        /// 復制sheet
        /// </summary>
        /// <param name="bjDt">sheet名集合</param>
        /// <param name="modelfilename">模板附件名</param>
        /// <param name="tpath">生成文件路徑</param>
        /// <returns></returns>
        public HSSFWorkbook SheetCopy(DataTable bjDt,string modelfilename, out string tpath)
        {
            string templetfilepath = @"files\" + modelfilename + ".xls";//模版Excel

            tpath = @"files\download\" + modelfilename + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".xls";//中介Excel，以它為中介來導出，避免直接使用模塊Excel而改變模塊的格式
            FileInfo ff = new FileInfo(tpath);
            if (ff.Exists)
            {
                ff.Delete();
            }
            FileStream fs = File.Create(tpath);//創建中間excel
            HSSFWorkbook x1 = new HSSFWorkbook();
            x1.Write(fs);
            fs.Close();
            FileStream fileRead = new FileStream(templetfilepath, FileMode.Open, FileAccess.Read);
            HSSFWorkbook hssfworkbook = new HSSFWorkbook(fileRead);
            FileStream fileSave2 = new FileStream(tpath, FileMode.Open, FileAccess.Read);
            HSSFWorkbook book2 = new HSSFWorkbook(fileSave2);
            HSSFWorkbook[] book=new HSSFWorkbook[2]{book2,hssfworkbook};
            HSSFSheet CPS = hssfworkbook.GetSheet("Sheet0") as HSSFSheet;//獲得模板sheet
            string rsbh=bjDt.Rows[0]["name"].ToString();
            CPS.CopyTo(book2,rsbh , true, true);//將模板sheet復制到目標sheet
            HSSFSheet sheet = book2.GetSheet(bjDt.Rows[0]["name"].ToString()) as HSSFSheet;//獲得當前sheet
            for (int i = 1; i < bjDt.Rows.Count; i++)
            {
                sheet.CopySheet(bjDt.Rows[i]["name"].ToString(), true);//將sheet復制到同一excel的其他sheet上
            }
            return book2;
        }

中介excel生成后進行數據填充

/// <summary>
        /// 將datatable數據導出到excel
        /// </summary>
        /// <param name="bjDt">sheet名集合</param>
        /// <param name="stuDt">填充數據</param>
        /// <param name="modelfilename">模板名</param>
        /// <returns></returns>
        public string DataTableToExcel(DataTable bjDt, DataTable stuDt,string modelfilename)
        {
            string path = "";
            HSSFWorkbook book2 = SheetCopy(bjDt,modelfilename,out path);
            for (int j = 0; j < bjDt.Rows.Count; j++)
            {
                HSSFSheet sheets = book2.GetSheet(bjDt.Rows[j]["name"].ToString()) as HSSFSheet;
                sheets.GetRow(1).GetCell(1).SetCellValue(bjDt.Rows[j]["name"].ToString());
                DataRow[] strDt = stuDt.Select(" name='" + bjDt.Rows[j]["name"].ToString() + "'");//篩選出對應的工作表下的數據
                int rowIndex = 4;
                for (int i = 0; i < strDt.Length;i++ )
                {
                    HSSFRow row0 = sheets.GetRow(rowIndex) as HSSFRow;  //第幾行
                    HSSFCell cell0 = row0.GetCell(0) as HSSFCell;   //第幾列
                    cell0.SetCellValue(strDt[i]["ID"].ToString()); //數據填充
                    rowIndex++;
                }
            }
            using (FileStream fileSave = new FileStream(path, FileMode.Open, FileAccess.Write))
            {
                book2.Write(fileSave);
            }
            return  path;
        }

下載excel

　　　　　void FileDown(string url)
        {
            string fileName = "test.xls";//客戶端保存的文件名
            string filePath = url;//路徑

            FileInfo fileInfo = new FileInfo(filePath);
            Response.Clear();
            Response.ClearContent();
            Response.ClearHeaders();
            Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
            Response.AddHeader("Content-Length", fileInfo.Length.ToString());
            Response.AddHeader("Content-Transfer-Encoding", "binary");
            Response.ContentType = "application/octet-stream";
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            Response.WriteFile(fileInfo.FullName);
            Response.Flush();
            Response.End();
        }

導出后excel如圖

本人菜鳥一枚如有不足之處請多包涵和提點。