特别注意： range.Text.ToString(); 和 range.Value2.ToString(); 的区别

如果Excell的单元格里面是日期，前面显示2015年05月10日；后面的显示42134

也就是说：Text 和Value2的不同。

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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 Microsoft.Office.Core;
using Microsoft.Office.Interop.Excel;

public partial class dingdan2_Default5 : System.Web.UI.Page
{
    string str日期;
    string str单号;
    string str运费支付方式;
    string str收货人;
    string str电话;
    string str购货单位;
    string str收货地址;
    string str制单人;
    string str销售业务员;
    string str财务部;
    string str物流货运组;
    string str仓储组;

    string[,] str索引 = new string[,];
    string[,] str数据 = new string[,];

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            ((MasterPage)Master).setDaohang("订单管理->导入订单");

        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        if ((FileUpload1.HasFile) && (null != FileUpload1.PostedFile))
        {
            this.ListBox1.Items.Clear();

            String fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
            String[] allowedExtensions = { ".xls" };
            for (int i = ; i < allowedExtensions.Length; i++)
            {
                if (fileExtension.ToLower() == allowedExtensions[i])
                {
                   this.Session["g_filename"] = FileUpload1.FileName;
                    this.FileUpload1.SaveAs(Server.MapPath("uploadfiles\\") + FileUpload1.FileName);
                    this.ListBox1.Items.Insert(, "文件上传成功!   " + FileUpload1.FileName);
                }
                else
                {
                    this.ListBox1.Items.Insert(, "只能上传EXCEL文件!" + FileUpload1.FileName);
                }

            }
        }
        else
        {
            this.ListBox1.Items.Insert(, "无法检测到上传的文件!");
        }

    }
    //Excel 应用程序对象
    Excel.Application ExcelRS;
    //Excel 工作簿对象
    Excel._Workbook RSbook;
    //Excel 工作页对象
    Excel._Worksheet RSsheet;
    //某一个单元格对象
    Excel.Range range;

    protected void Button2_Click(object sender, EventArgs e)
    {
        try
        {
            //第一步:建立Excel应用程序
            ExcelRS = new Excel.Application();
            this.ListBox1.Items.Insert(, "建立Excel应用程序成功!");

            //第二步:建立Excel工作簿
            RSbook = (Excel._Workbook)ExcelRS.Workbooks.Open(Server.MapPath("uploadfiles\\")+this.Session["g_filename"].ToString(), Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            this.ListBox1.Items.Insert(, "建立Excel工作簿成功!");

            //第三步:设置第一个工作溥
            RSsheet = (Excel._Worksheet)RSbook.Sheets.get_Item();
            this.ListBox1.Items.Insert(, "建立Excel工作页成功!");

            //第四步:读取数据
            range = (Excel.Range)RSsheet.get_Range("B2", Type.Missing);
            this.str日期 = range.Text.ToString();
            this.ListBox1.Items.Insert(,"日期:"+this.str日期);

            range = (Excel.Range)RSsheet.get_Range("G2", Type.Missing);
            this.str单号= range.Value2.ToString();
            this.ListBox1.Items.Insert(, "单号:" + this.str单号);

            range = (Excel.Range)RSsheet.get_Range("B3", Type.Missing);
            this.str运费支付方式 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "运费支付方式:" + this.str运费支付方式);

            range = (Excel.Range)RSsheet.get_Range("D3", Type.Missing);
            this.str收货人 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "收货人:" + this.str收货人);

            range = (Excel.Range)RSsheet.get_Range("G3", Type.Missing);
            this.str电话 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "电话:" + this.str电话);

            range = (Excel.Range)RSsheet.get_Range("B4", Type.Missing);
            this.str购货单位 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "购货单位:" + this.str购货单位);

            range = (Excel.Range)RSsheet.get_Range("B5", Type.Missing);
            this.str收货地址 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "收货地址:" + this.str收货地址);

            range = (Excel.Range)RSsheet.get_Range("B15", Type.Missing);
            this.str制单人 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "制单人:" + this.str制单人);

            range = (Excel.Range)RSsheet.get_Range("E15", Type.Missing);
            this.str销售业务员 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "销售业务员:" + this.str销售业务员);

            range = (Excel.Range)RSsheet.get_Range("I15", Type.Missing);
            this.str财务部 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "财务部:" + this.str财务部);

            range = (Excel.Range)RSsheet.get_Range("B16", Type.Missing);
            this.str物流货运组 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "物流货运组:" + this.str物流货运组);

            range = (Excel.Range)RSsheet.get_Range("E16", Type.Missing);
            this.str仓储组 = range.Value2.ToString();
            this.ListBox1.Items.Insert(, "仓储组:" + this.str仓储组);

            for (int i = ; i < ; i++)
            {
                str索引[i - , ] = "A" + i.ToString();
                str索引[i - , ] = "B" + i.ToString();
                str索引[i - , ] = "C" + i.ToString();
                str索引[i - , ] = "D" + i.ToString();
                str索引[i - , ] = "E" + i.ToString();
                str索引[i - , ] = "F" + i.ToString();
                str索引[i - , ] = "G" + i.ToString();
                str索引[i - , ] = "H" + i.ToString();
                str索引[i - , ] = "I" + i.ToString();
                str索引[i - , ] = "J" + i.ToString();
            }

            //读取数据
            for (int i = ; i < ; i++)
            {
                for (int j = ; j < ; j++)
                {
                    range  = (Excel.Range)RSsheet.get_Range(str索引[i,j], Type.Missing);
                    str数据[i,j] = range.Text.ToString();
                    this.ListBox1.Items.Add(i.ToString() + ":" + j.ToString() + "=" + str数据[i, j]);
                }
            }

        }
        catch (System.Exception ex)
        {
            this.ListBox1.Items.Insert(,"异常! "+ex.ToString() + "-" +ex.Message +"-"+ex.Source);
        }
        finally
        {
            ExcelRS.Quit();
        }

    }
}