返回excel表的工作表表名数组
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;
    }

把excel返回dataset
 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 );
        return ds ;
    }

使用实例：
 DataSet ds = new DataSet();
        ds = ExcelDataSource("|DataDirectory|student.xls;", ExcelSheetName("|DataDirectory|student.xls;")[0].ToString());

        if (ds.Tables[0] != null && ds.Tables[0].Rows.Count > 0)
        {
            for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
            {
                string UserName = ds.Tables[0].Rows[i][0].ToString().Trim();
                string Userpwd = "123456";
                string realname = ds.Tables[0].Rows[i][0].ToString().Trim();
                string Phone = "13526447060";
                string sex = ds.Tables[0].Rows[i][1].ToString().Trim();
                string homepage = ds.Tables[0].Rows[i][4].ToString().Trim();
                string Question = ds.Tables[0].Rows[i][2].ToString().Trim();
                string Answer = ds.Tables[0].Rows[i][3].ToString().Trim();
              

                using (OleDbConnection conn = new OleDbConnection(sConnectionString))
                {
                    conn.Open();
                    using (OleDbCommand cmd = new OleDbCommand("insert into jd_user ([UserName],Userpwd,realname,Phone,ispass,sex,homepage,Question,Answer) values (@UserName,@Userpwd,@realname,@Phone,@ispass,@sex,@homepage,@Question,@Answer)", conn))
                    {
                        //sex,homepage,Question,Answer
                        cmd.Parameters.AddWithValue("@UserName", UserName);
                        cmd.Parameters.AddWithValue("@Userpwd", Jdpc.Encrypt.jiami(Userpwd));
                        cmd.Parameters.AddWithValue("@realname", realname);
                        cmd.Parameters.AddWithValue("@Phone", Phone);
                        cmd.Parameters.AddWithValue("@ispass", 1);
                        cmd.Parameters.AddWithValue("@sex", sex);
                        cmd.Parameters.AddWithValue("@homepage", homepage);
                        cmd.Parameters.AddWithValue("@Question", Question);
                        cmd.Parameters.AddWithValue("@Answer", Answer);

                        cmd.ExecuteNonQuery();
                    }

                    //Page.ClientScript.RegisterStartupScript(this.GetType(), "", "alert('注册成功，等待审核！');", true);
                }

            }
        }