急问题There is already an open DataReader associated with this Command which must b

Question

做了一个小网站，有时候会出这个问题，知道应该是个常见的问题，但也不太清楚如何解决，请高手指点啊！
There is already an open DataReader associated with this Command which must be closed first.调用底层代码：（还请高手指点不足之处，先谢谢了！）
        public static DataTable GetDataTable(string contype, string sql, string tname)
        {
            DataTable dt = new DataTable();
            using (SqlConnection conn = GetConnection(contype))
            {
                SqlCommand comm = new SqlCommand();
                try
                {
                    comm.Connection = conn;
                    comm.CommandText = sql;
                    comm.CommandTimeout = 100;
                    using (SqlDataAdapter da = new SqlDataAdapter(comm))
                    {
                        da.Fill(dt);
                    }
                }
                catch (Exception ee)
                {
                    throw new Exception(ee.Message);
                }
                finally
                {
                    comm.Dispose();
                    conn.Close();
                    conn.Dispose();
                }
            }
            return dt;
        }
       /// <summary>
        /// 通过 SqlParameter[] 得到表
        /// </summary>
        /// <param name="contype">数据库连接的名字</param>
        /// <param name="procName">存储过程名称</param>
        /// <param name="tname">表名</param>
        /// <param name="paras">存储过程的值</param>
        /// <returns>表</returns>
        public static DataTable GetDataTable(string contype, string procName, string tname, SqlParameter[] paras)
        {
            using (SqlConnection conn = GetConnection(contype))
            {
               // SqlDataAdapter da = null;
                DataTable dt = new DataTable();
                SqlCommand comm = new SqlCommand();
                try
                {
                    comm.Connection = conn;
                    comm.CommandText = procName;
                    comm.CommandTimeout = 100;
                    if (paras != null)
                    {
                        comm.CommandType = CommandType.StoredProcedure;
                        foreach (SqlParameter para in paras)
                        {
                            comm.Parameters.Add(para);
                        }
                    }
                    using (SqlDataAdapter da = new SqlDataAdapter(comm))
                    {
                        da.Fill(dt);
                    }
                }
                catch (Exception ex) { throw new Exception(ex.Message); }
                finally
                {
                    comm.Dispose();
                    conn.Close();
                    conn.Dispose();
                }
                return dt;
            }
        }

Answer 1

找你代码里有没有用DataReader来取数据的，看看那里用完有没有close connection

Answer 2

我感觉问题不在你这俩函数里ba ?
应该是DAtaReader用完了但是没有关闭的问题，

Answer 3

关键的问题就是在这了，我代码里真的没有用到过DataReader啊！

Answer 4

就是这个Catch抓住的异常，高手在帮忙看看吧
    /// <summary>
    /// 活动快报前5条记录
    /// </summary>
    /// <returns></returns>
    public string selectReport()
    {
        int news_id = 0;//新闻ID
        string news_title = string.Empty;//新闻标题        StringBuilder sbr = new StringBuilder();
        DataTable dt = new DataTable();
        string sql = "select top 13 id,title from News where BigClassName='活动快报' order by red desc,infotime desc";
        //string sql = "select top 5 id,title from News order by infotime desc";
        try
        {
            sbr.Append("<ul>\n");
            dt = DBUtility.DataBase.GetDataTable("one", sql, "News");
            int i = 0;
            foreach (DataRow row in dt.Rows)
            {
                news_id = Convert.ToInt32(row["id"].ToString());
                news_title = row["title"].ToString();
                if (i == 0)
                {
                    sbr.Append("<li class=\"FONTsize\"><a href=\"/2009/News.aspx?id=" + news_id + "\"><B>" + news_title + "</B></a></li>\n");
                }
                else
                {
                    if (i % 2 == 0)
                    {
                        sbr.Append("<td width=\"50%\">\n");
                        sbr.Append("<a href=\"/2009/News.aspx?id=" + news_id + "\" title=\"" + news_title + "\">" + ExaminesList.GetString(news_title, 30) + "</a>\n");
                        sbr.Append("</td>\n</tr>\n</table>\n");
                        sbr.Append("</li>\n");
                    }
                    else
                    {
                        sbr.Append("<li>\n");
                        sbr.Append("<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"396\">\n<tr>\n<td width=\"50%\">\n");
                        sbr.Append("<a href=\"/2009/News.aspx?id=" + news_id + "\" title=\"" + news_title + "\">" + ExaminesList.GetString(news_title, 30) + "</a>\n");
                        sbr.Append("</td>\n");
                    }
                }
                i++;
            }
            if (i % 2 == 0)
            {
                sbr.Append("<td width=\"50%\">\n");
                sbr.Append("</td>\n</tr>\n</table>\n");
                sbr.Append("</li>\n");
            }
            sbr.Append("</ul>\n");
        }
        catch (Exception ex)
        {
            HttpContext.Current.Response.Write(ex.Message);
            HttpContext.Current.Response.End();
        }
        finally
        {
            if (dt != null)
            {
                dt.Dispose();
            }
        }
        return sbr.ToString();
    }

Answer 5

而且看你的command和connection都是新创建的，好像也没啥问题啊。

Answer 6

这个就是网站的异常信息，其它没什么了，搞得我郁闷
There is already an open DataReader associated with this Command which must be closed first. 

Answer 7

web.config中
<customErrors mode="Off" >然后运行页面，看页面中下部的提示

Answer 8

那执行上面代码是先判断一下conn是不是打开是打开的就先关闭，然后再打开。就像这样：
  SqlConnection conn = new SqlConnection();
            if (conn.State == ConnectionState.Open)
            {
                conn.Close();
            }
            conn.Open();
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