asp.net(C#)套用模板操作Excel

当需要输出带大量公式的Excel文档的时候，在代码里写公式就太累了。
用设计好的Excel模板，复制一下，往里面添加数据比较省事。
模板

导出文件：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.IO;
using System.Reflection;
using Microsoft.Office.Interop.Excel;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            Bind();
    }
    private void Bind()
    {
        //模板文件
        string TempletFileName = Server.MapPath("template/") + "template.xlsx";
        //导出文件
        string ReportFileName = Server.MapPath("xls/") + "out.xlsx";

        string strTempletFile = Path.GetFileName(TempletFileName);
        //将模板文件复制到输出文件 
        FileInfo mode = new FileInfo(TempletFileName);
        mode.CopyTo(ReportFileName, true);

        //打开excel
        object missing = Missing.Value;
        Application app = null;
        Workbook wb = null;
        Worksheet ws = null;
        Range r = null;
        //
        app = new Microsoft.Office.Interop.Excel.Application();
        wb = app.Workbooks.Open(ReportFileName, false, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing);
        app.Visible = true;

        //得到WorkSheet对象
        ws = (Worksheet)wb.Worksheets.get_Item(1);

        //添加或修改WorkSheet里的数据
        ws.Cells[1, 1] = "100";
        ws.Cells[2, 1] = "100";
        ws.Cells[2, 2] = "100";
        //代码里写个公式
        r = (Range)ws.Cells[2, 3];
        r.Formula = "=A2*B2";

        //输出Excel文件并退出
        wb.Save();
        wb.Close(null, null, null);
        app.Workbooks.Close();
        app.Application.Quit();
        app.Quit();

        System.Runtime.InteropServices.Marshal.ReleaseComObject(ws);
        System.Runtime.InteropServices.Marshal.ReleaseComObject(wb);
        System.Runtime.InteropServices.Marshal.ReleaseComObject(app);

        ws = null;
        wb = null;
        app = null;
    }
}

参考：

C#操作Excel，套用模板并对数据进行分页