求助关于SetParameter的问题!

    /// <summary>
        /// 为Command变量设置参数
        /// </summary>
        /// <param name="DBName">名称</param>
        /// <param name="DBValue">值</param>
        /// <param name="dbtype">类型</param>
        public void SetParameter(string DBName,object DBValue,SqlDbType dbtype)
        {
            try
            {
                if (dbtype == SqlDbType.UniqueIdentifier)
            {
                    this.m_Cmd.Parameters.Add(new SqlParameter(DBName,dbtype));
                    this.m_Cmd.Parameters[DBName].Value = new Guid(DBValue.ToString());                  

                }
            else
            {
                    this.m_Cmd.Parameters.Add(new SqlParameter(DBName,dbtype));
                    this.m_Cmd.Parameters[DBName].Value = DBValue;
                }
            }
            catch (Exception err)
            {           
                ErrLog.WriteErrLog("设置参数不成功：参数名称=" + DBName + "；参数值=" + DBValue.ToString() + "错误信息=" + err.Message);
            }
        }

    cmmgr.SetParameter("@Number5", number.T_Number5, SqlDbType.Int);  //此句调用上面的

    我调试了发现this.m_Cmd.Parameters[DBName].Value的值是正确的，但是我的数据库中Number5的值老是更新不了。有没有高手能帮我解答一下！谢谢