1 private  SqlConnection conn;
 2         public  SqlConnection Conn 
 3         {
 4             get 
 5             {
 6                 if (conn == null)
 7                 {
 8                     string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
 9                     conn = new SqlConnection(connStr);
10                 }
11                 if (conn.State == ConnectionState.Closed)
12                     conn.Open();
13                 if (conn.State == ConnectionState.Broken)
14                 {
15                     conn.Close();
16                     conn.Open();
17                 }
18                 return conn; 
19             }
20         }

 1   //查询:DataReader
 2         public  SqlDataReader GetReader(string sql)
 3         {
 4            SqlCommand cmd = new SqlCommand(sql, Conn);
 5            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
 6         }
 7         public  SqlDataReader GetReader(string sql,SqlParameter[] paras)
 8         {
 9             SqlCommand cmd = new SqlCommand(sql, Conn);
10             cmd.Parameters.AddRange(paras);
11