求手写分页函数C#

/**////
/// 返回数据集
///
///
///
public DataSet GetData(string sql,string strconn)
{
OleDbConnection ole=new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA Source="+strconn);
ole.Open();
OleDbCommand cm=new OleDbCommand(sql,ole);
DataSet ds=new DataSet();
OleDbDataAdapter da=new OleDbDataAdapter(cm);
da.Fill(ds);
ole.Close();
return ds;
}

/**//// <summary>
/// 分页
/// </summary>
/// <param name="pagesize">每页大小</param>
/// <param name="pageindex">当前页数</param>
/// <param name="field">获取字段名</param>
/// <param name="tablename">表名</param>
/