string ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + FileName + ";Extended Properties=\"Excel 8.0;HDR=no;IMEX=0\"";
            string StrSQL = "SELECT * FROM [Sheet1$]";
            System.Data.OleDb.OleDbDataAdapter DataAda = new System.Data.OleDb.OleDbDataAdapter(StrSQL, ConnectionString);
            DataSet DSTemp = new DataSet();
            DataAda.Fill(DSTemp);
            DataAda.Dispose();

------解决方案--------------------
我推荐 npoi

------解决方案--------------------
这是我写的一个方法
C# code

    /// <summary>
        /// 获取excel数据，返回一个dateset
        /// </summary>
        /// <param name="filePath">excel的物理路径</param>
        /// <param name="sheet">第几个sheet</param>
        /// <returns></returns>
        public static DataSet LoadDataFromExcel(string filePath, int sheet)
        {
            try
            {
                string strConn = "";
                if (filePath.EndsWith("xls"))
                    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";
                else if (filePath.EndsWith("xlsx"))
                    strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";
                else
                    return null;
                OleDbConnection OleConn = new OleDbConnection(strConn);
                OleConn.Open();
                String sql = "SELECT * FROM  [Sheet" + sheet + "$]";//可是更改Sheet名称，比如sheet2，等等   

                OleDbDataAdapter OleDaExcel = new OleDbDataAdapter(sql, OleConn);
                DataSet OleDsExcle = new DataSet();
                OleDaExcel.Fill(OleDsExcle, "Sheet" + sheet);
                OleConn.Close();
                return OleDsExcle;
            }
            catch (Exception err)
            {
                return null;
            }
        }

------解决方案--------------------
SpreadsheetGear/farPoint

------解决方案--------------------
在C#.net中定义和使用自己的特性

------解决方案--------------------
http://ufo-crackerx.blog.163.com/blog/static/11307877820119238517149/

http://www.e-iceblue.com/Download/download-office-for-net-now.html

------解决方案--------------------
http://ufo-crackerx.blog.163.com/blog/static/1130787782011112010495744/