ASP.NET中读取Excel内容，并显示在界面上

   客户端上传本地excel文件到服务器上，并在客户端显示。

  // 上传按钮  
   protected void btnUp_Click(object sender, EventArgs e)
   {
       bool b = Upload(fuExcel);  // 上传excel文件 
       if (!b)
       {
           return;
       }
       string name = fuExcel.FileName;
       string filepath = Server.MapPath("~/upload/") + name;
       DataSet ds = ExcelDataSource(filepath, ExcelSheetName(filepath)[0].ToString());
       GridView1.DataSource = ds;
       GridView1.DataBind();
   }

   //上传文件方法  
   private bool Upload(FileUpload myFileUpload)
   {
       bool flag = false;
       //是否允许上载  
       bool fileAllow = false;
       //设定允许上载的扩展文件名类型  
       string[] allowExtensions = { ".xls" };

       //取得网站根目录路径  
       string path = HttpContext.Current.Request.MapPath("~/upload/");
      if (myFileUpload.HasFile)
       { string fileExtension = System.IO.Path.GetExtension(myFileUpload.FileName).ToLower();
        for (int i = 0; i < allowExtensions.Length; i++)
           {
               if (fileExtension == allowExtensions[i])
               {
                   fileAllow = true;
               }
           }

           if (fileAllow)
           {
               try
               {
                   //存储文件到文件夹 
                   myFileUpload.SaveAs(path + myFileUpload.FileName);
                   lblMes.Text = "文件导入成功";
                   flag = true;
               }
               catch (Exception ex)
               {
                   lblMes.Text += ex.Message;
                   flag = false;
               }
           }
           else
           {
               lblMes.Text = "不允许上载：" + myFileUpload.PostedFile.FileName + "，只能上传xls的文件，请检查！";
               flag = false;
           }
       }
       else
       {
           lblMes.Text = "请选择要导入的excel文件!";
           flag = false;
       }
       return flag;
   }

   //该方法实现从Excel中导出数据到DataSet中，其中filepath为Excel文件的绝对路径， sheetname为excel文件中的表名

public DataSet ExcelDataSource(string filepath, string sheetname)
   {
       string strConn;
       strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filepath + ";Extended Properties=Excel 8.0;";
       OleDbConnection conn = new OleDbConnection(strConn);
       OleDbDataAdapter oada = new OleDbDataAdapter("select * from [" + sheetname + "]", strConn);
       DataSet ds = new DataSet();
       oada.Fill(ds);
       conn.Close();
       return ds;
   }

   //获得Excel中的所有sheetname。
   public ArrayList ExcelSheetName(string filepath)
   {
       ArrayList al = new ArrayList();
       string strConn;
       strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filepath + ";Extended Properties=Excel 8.0;";
       OleDbConnection conn = new OleDbConnection(strConn);
       conn.Open();
       DataTable sheetNames = conn.GetOleDbSchemaTable
       (System.Data.OleDb.OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
       conn.Close();
       foreach (DataRow dr in sheetNames.Rows)
       {
           al.Add(dr[2]);
       }
       return al;
   } 

也可以在webconfig文件里面指定连接字符串的参数：

<connectionStrings>

    <add name="xls"connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Sample1.xls;Extended Properties=Excel 8.0"/>

    <add name="xlsx"connectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Sample.xlsx;Extended Properties=Excel 12.0"/>

  </connectionStrings>

用

string connString = ConfigurationManager.ConnectionStrings["xls"].ConnectionString;

注意XP下文件操作权限的问题。