C#操作数据表中XML格式的数据

以前还真没有见过数据表中存储XML格式的数据，刚开始听说的时候，还以为是数据表中有XML的字段类型，

再了解，其实也就是字符串类型的，只不过字符串的格式是XML格式的。确实孤陋寡闻！汗...

(可添加多个时间)

（xml的格式可以自己定义的）

一、如何存储XML格式的数据到表中：

1、定义相关实体类

    /// <summary>
    /// 营业时间实体
    /// </summary>
    [XmlRoot("r")]
    public class OpenHoursEntity
    {
        /// <summary>
        /// 营业时间集合
         /// </summary>
        [XmlElement("ts")]
        public List<OpenHours> OpenHoursList { get; set; }
    }

    /// <summary>
    /// 营业时间
    /// </summary>
    public class OpenHours
    {
        /// <summary>
        /// 营业开始时间
         /// </summary>
        [XmlElement("b")]
        public string BeginTime { get; set; }
        /// <summary>
        /// 营业结束时间
         /// </summary>
        [XmlElement("e")]
        public string EndTime { get; set; }
    }

2、保存

        /// <summary>
        /// 生成XML，不包含声明和命名空间
         /// </summary>
       /// <typeparam name="T">对象类型</typeparam>
       /// <param name="obj">对象</param>
       /// <returns>xml字符串</returns>
       public static string SerializeOnlyXml<T>(T obj)
        {
            var serializer = new XmlSerializer(typeof(T));
            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Encoding = new UTF8Encoding(false);
            settings.OmitXmlDeclaration = true;
            // 强制指定命名空间，覆盖默认的命名空间。
              XmlSerializerNamespaces namespaces = new XmlSerializerNamespaces();
            namespaces.Add(string.Empty, string.Empty);
            var stream = new MemoryStream();
            using (XmlWriter writer = XmlWriter.Create(stream, settings))
            {
                serializer.Serialize(writer, obj, namespaces);
            }
            return Encoding.UTF8.GetString(stream.ToArray());
        }

     Table1 model =new Table1();//数据表对应的实体
      OpenHoursEntity entity = new OpenHoursEntity();//营业时间实体
      entity.OpenHoursList = new List<OpenHours>();
     if (!string.IsNullOrEmpty(lblOpeningHours.Text.Trim()))
     {
         if (lblOpeningHours.Text.Trim().Contains(","))
         {
             foreach (string item in lblOpeningHours.Text.Trim().Trim(',').Split(','))
             {
                 OpenHours openhours = new OpenHours();
                 openhours.BeginTime = item.Split('~')[0];
                 openhours.EndTime = item.Split('~')[1];
                 entity.OpenHoursList.Add(openhours);
             }
         }
         else
         {
             OpenHours openhours = new OpenHours();
             openhours.BeginTime = lblOpeningHours.Text.Trim().Split('~')[0];
             openhours.EndTime = lblOpeningHours.Text.Trim().Split('~')[1];
             entity.OpenHoursList.Add(openhours);
         }
     }
　　  model.STPESortName="营业时间";
　　  model.STPEExtendName=SerializeOnlyXml<OpenHoursEntity>(entity);
     Add(model);//保存到数据库

二、读取数据表中XML格式的数据并显示

        /// <summary>
        /// 将对象序列化为xml字符串
         /// </summary>
       /// <typeparam name="T">对象类型</typeparam>
       /// <param name="obj">对象</param>
       /// <returns>xml字符串</returns>
       public static string Serialize<T>(T obj)
       {
           //序列化实体
             var serializer = new XmlSerializer(typeof(T));
           //注意如果不设置encoding默认将输出utf-16
           //注意这儿不能直接用Encoding.UTF8如果用Encoding.UTF8将在输出文本的最前面添加4个字节的非xml内容
             var stream = new MemoryStream();
           using (XmlWriter writer = XmlWriter.Create(stream, new XmlWriterSettings { Encoding = new UTF8Encoding(false) }))
           {
               serializer.Serialize(writer, obj);
           }
           return Encoding.UTF8.GetString(stream.ToArray());
       }

 显示已有的时间：

          var obj = TCSmartFramework.Utility.XMLHelper.GetObjFromXML<OpenHoursEntity>(ConvertHelper.ToString(dt.Rows[0]["STPEExtendName"]), Encoding.UTF8);
       StringBuilder sbTime = new StringBuilder();
       for (int i = 0; i < obj.OpenHoursList.Count(); i++)
       {
            sbTime.Append(obj.OpenHoursList[i].BeginTime + "~" + obj.OpenHoursList[i].EndTime).Append(',');
       }
       lblOpeningHours.Text = sbTime.ToString();