ExecuteReader：连接错误消息

Question

我想在文本框中显示数据，但 运行 我的 DAL 出现错误。我有一个存储过程，但我无法将我的数据获取到 return 值中的 return。我想用我的 BLL 到 return 一个数据表。你能帮忙吗？

DAL

public static string GetTicket(collection b)
        {
            try
            {

                string returnValue = string.Empty;
                DB = Connect();
                DBCommand = connection.Procedure("getTicket");
                DB.AddInParameter(DBCommand, "@SupportRef", DbType.String, b.SupportRef1);

                var myReader = DBCommand.ExecuteReader();
                while (myReader.Read())
                {
                    returnValue = myReader.GetString(0);
                }

                return returnValue;
            }

            catch (Exception ex)
            {
                throw ex;
            }

        }

我收到以下错误：

ExecuteReader: Connection property has not been initialized.

我正在使用如下所示的连接 class：

public class connection
{
    const string StrConnection = "TicketHelperConnectionString";
    internal static Database DB;
    public static DbCommand DBCommand;
    public static Database Connect()
    {

        try
        {
            DB = DatabaseFactory.CreateDatabase(StrConnection);
            return DB;
        }
        catch (Exception ex)
        {
            throw (ex);
        }
    }
    public static DbCommand Procedure(string procedure)
    {

        try
        {
            DBCommand = DB.GetStoredProcCommand(procedure);
            return DBCommand;
        }
        catch (Exception ex)
        {
            throw (ex);            
        }
    }
}

Answer 1

看起来 DBCommand 的连接 属性 没有设置，在你 return 来自 Procedure 方法的命令之前你必须设置它的连接 属性:

DBCommand = DB.GetStoredProcCommand(procedure);

// DBCommand.Connection = ...

return DBCommand;