这是什么问题？在线等，急~~~~

Question

OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; " + "Data Source=" + Server.MapPath("data/Dvbbs7.mdb"));
OleDbCommand cmd = new OleDbCommand("Select * FROM Dv_Topic where isbest = 1",conn);
conn.Open();
OleDbDataReader reader = cmd.ExecuteReader();
dv_best = "";
while(reader.Read())
{
dv_best = "<tr>"
+"<td height=22><img src=images/dian.gif width=8 height=8><a href=\"#\" target=\"_blank\">"+sdr["Title"].ToString()+"</a></td>"
+"<td><font color=#666666>"+sdr["PostUserName"].ToString()+"</font></td>"
+"</tr>";
}
reader.Close();
conn.Open();

Answer 1

错误提示是“阅读器关闭时READ无效”