ASP.Net动态读取Excel文件最简方法

注意：页面分别拖拽一个fileupload、button1、label1、gridview控件，并新建一个uploadedexcel文件夹

default.aspx.cs代码：

using system;
using system.collections.generic;
using system.data;
using system.data.oledb;
using system.io;
using system.linq;
using system.web;
using system.web.ui;
using system.web.ui.webcontrols;

namespace webapplication2
{
  public partial class webform1 : system.web.ui.page
  {
    protected void page_load(object sender, eventargs e)
    {
       delete();
    }

    protected void button1_click(object sender, eventargs e)
    {
      oledbconnection conn = new oledbconnection();
      oledbcommand cmd = new oledbcommand();
      oledbdataadapter da = new oledbdataadapter();
      dataset ds = new dataset();
      string query = null;
      string connstring = "";
      string strfilename = datetime.now.tostring("ddmmyyyy_hhmmss");
      //string strfilename = path.getfilenamewithoutextension(fileupload1.postedfile.filename);
      string strfiletype = path.getextension(fileupload1.filename).tostring().tolower();
      if (strfiletype == ".xls" || strfiletype == ".xlsx")
      {
        fileupload1.saveas(server.mappath("~/uploadedexcel/" + strfilename + strfiletype));
      }
      else
      {
        return;
      }
      string strnewpath = server.mappath("~/uploadedexcel/" + strfilename + strfiletype);
      if (strfiletype.trim() == ".xls")
      {
        connstring = "provider=microsoft.jet.oledb.4.0;data source=" + strnewpath + ";extended properties=\"excel 8.0;hdr=yes;imex=2\"";
      }
      else if (strfiletype.trim() == ".xlsx")
      {
        connstring = "provider=microsoft.ace.oledb.12.0;data source=" + strnewpath + ";extended properties=\"excel 12.0;hdr=yes;imex=2\"";
      }
      query = "select * from [sheet1$]";
      conn = new oledbconnection(connstring);
      if (conn.state == connectionstate.closed)
      {
        conn.open();
      }
      try
      {
        cmd = new oledbcommand(query, conn);
        da = new oledbdataadapter(cmd);
        ds = new dataset();
        da.fill(ds);
        gridview1.datasource = ds.tables[0];
        gridview1.databind();
        label1.text = "读取成功";
      }
      catch (exception ex)
      {
        label1.text = "读取失败";
        response.write(ex);
      }
      finally
      {
        da.dispose();
        conn.close();
        conn.dispose();
      }
    }
    //定时任务
    private void delete()
    {
      directoryinfo di = new directoryinfo(server.mappath("/uploadedexcel/"));
      fileinfo[] fi = di.getfiles("*." + "*");
      datetime dtnow = datetime.now;
      foreach (fileinfo tmpfi in fi)
      {
        timespan ts = dtnow.subtract(tmpfi.lastwritetime);
        if (ts.milliseconds > 100)
        {
          tmpfi.attributes = fileattributes.normal;
          tmpfi.delete();
        }
      }
    }
  }
}

注意：fileupload控件并不能直接获取到文件的绝对路径（ie6及以下除外），只能通过上传到服务器再进行数据加载，然后再删除