已有打开的与此 Command 相关联的 DataReader，必须首先将它关闭。该如何处理

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protected string sConnString = "...";   // 连接数据库字符串protected void Page_Load(object sender, EventArgs e){      menu.InnerHtml = CreateMenuHtml();        }public string CreateMenuHtml(){      StringBuilder sMenuHtml = new StringBuilder();      if(isPurview("itemA")) { sMenuHtml.append(...) ......}      if(isPurview("itemB")) { sMenuHtml.append(...) ......}      if(isPurview("itemC")) { sMenuHtml.append(...) ......}      if(isPurview("itemD")) { sMenuHtml.append(...) ......}      if(GetOther("@ABlock", "ABlock")==1) { sMenuHtml.append(...) ......} // 添上了这句就出现如题的错误。       return sMenuHtml.ToString();}//public bool isPurview(string item){            SqlConnection connection = new SqlConnection(this.sConnString);            SqlCommand command = new SqlCommand("IS_Purview", connection);            command.CommandType = CommandType.StoredProcedure;            SqlParameter username = command.Parameters.Add("@sUserName", SqlDbType.Char, 50);            SqlParameter purview = command.Parameters.Add("@sPurview", SqlDbType.Char, 50);            SqlParameter intReturn = command.Parameters.Add("rv", SqlDbType.Int);            username.Direction = ParameterDirection.Input;            purview.Direction = ParameterDirection.Input;            intReturn.Direction = ParameterDirection.ReturnValue;            username.Value = Session["username"].ToString();            purview.Value = item;            if (connection.State == ConnectionState.Closed)            {                connection.Open();            }                        SqlDataReader reader = command.ExecuteReader();            int returnValue = int.Parse(command.Parameters["rv"].Value.ToString());            reader.Close();            connection.Close();            if (returnValue == 1)                return true;            else                return false; }  public int GetOther(string item, string itemvalue){            int iOther=0;            SqlConnection connection = new SqlConnection(this.sConnString);            SqlCommand command = new SqlCommand("IS_Other", connection);            command.CommandType = CommandType.StoredProcedure;            SqlParameter OtherList = command.Parameters.Add(item, SqlDbType.Char, 50);            OtherList.Direction = ParameterDirection.Input;            OtherList.Value = itemvalue;            if (connection.State == ConnectionState.Closed)            {                connection.Open();            }            SqlDataReader reader = command.ExecuteReader();            reader = command.ExecuteReader();            if (reader.Read())            {                iOther = Convert.ToInt32(reader[0]);            }            reader.Close();            connection.Close();            return iOther;}

加上try..catch..finally，比如：public bool isPurview(string item){            int returnValue=0;            SqlConnection connection = new SqlConnection(this.sConnString);            SqlDataReader reader =null;            SqlCommand command = new SqlCommand("IS_Purview", connection);            command.CommandType = CommandType.StoredProcedure;            SqlParameter username = command.Parameters.Add("@sUserName", SqlDbType.Char, 50);            SqlParameter purview = command.Parameters.Add("@sPurview", SqlDbType.Char, 50);            SqlParameter intReturn = command.Parameters.Add("rv", SqlDbType.Int);            username.Direction = ParameterDirection.Input;            purview.Direction = ParameterDirection.Input;            intReturn.Direction = ParameterDirection.ReturnValue;                        purview.Value = item;            try            {            username.Value = Session["username"].ToString();            if (connection.State == ConnectionState.Closed)            {                connection.Open();            }                         reader = command.ExecuteReader();             returnValue = int.Parse(command.Parameters["rv"].Value.ToString());            reader.Close();            connection.Close();          }          catch(Exception ex)          {             throw ex;          }          finally          {             if(reader!=null) reader.Close();             connection.Close();          }          return returnValue == 1;                 }  后面的GetOther也做类似的修改