如何把List<T>转成XML操作、增删改查

网上借鉴了一部分、不全、有的方法没有给出、自己瞎补的、反正能用！

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using System.Reflection;
using System.Windows.Forms;


namespace BaiDuRankCollection
{


    //    XmlUtils<User>.UpdateXmlItem(User);
    //XmlUtils<User>.DeleteXMLItem(User);

    //List<User> users= XmlUtils<User>.GetList();
    //List<User> users= XmlUtils<User>.GetListByCondition(new String[] {},new String[] {},true);
    //List<User> users= XmlUtils<User>.GetListByCondition(new String[] { "Name" },new String[] { "测" },false);
    //List<User> users= XmlUtils<User>.GetListByCondition(new String[] { "Name","Id" },new String[] { "测试","1" },true);

 


    /// <summary>
    /// 通用的 XML 操作类 （微型本地xml数据库）
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class XmlUtils<T>
    {
        /// <summary>  
        /// xml 保存路径  
        /// </summary>  
        private static readonly string xmlPath =  Application.StartupPath + @"XmlMOdel";
        /// <summary>  
        /// 主键名  
        /// </summary>  
        public static readonly string primaryPropertyName = "Id";


        /// <summary>  
        /// 创建xml文件  
        /// </summary>  
        /// <param name="t"></param>  
        public static void CreateXMLFile(T t)
        {
            string className = ReflectionUtils<T>.GetClassName(t);
            XmlDocument xmldoc = new XmlDocument();

            //加入XML的声明段落  
            XmlNode xmlnode = xmldoc.CreateNode(XmlNodeType.XmlDeclaration,"","");
            xmlnode.Value = "version="1.0" encoding="utf-8"";
            xmldoc.AppendChild(xmlnode);

            //加入一个根元素  
            XmlElement xmlelem = xmldoc.CreateElement("Root");
            //XmlText xmltext = xmldoc.CreateTextNode ( "Root Text" ) ;  
            //xmlelem.AppendChild ( xmltext ) ;  
            xmldoc.AppendChild(xmlelem);
            if (!Directory.Exists(xmlPath))
            {
                Directory.CreateDirectory(xmlPath);
            }
            xmldoc.Save(xmlPath + className + ".xml");
        }

        /// <summary>  
        /// 判断主键是否唯一  
        /// </summary>  
        /// <param name="xmldoc"></param>  
        /// <param name="className"></param>  
        /// <param name="o"></param>  
        /// <returns></returns>  
        private static Boolean IsPrimaryKeyUnique(XmlDocument xmldoc,string className,Object o)
        {
            string xPathStr = "Root/" + className + "[" + primaryPropertyName + "='" + o.ToString() + "']";
            // XPath 查询  
            XmlNodeList nodeList = xmldoc.SelectNodes(xPathStr);
            if (nodeList.Count > 0)
            {
                return false;
            }
            else
            {
                return true;
            }

        }

        /// <summary>  
        /// 插入对象  
        /// </summary>  
        /// <param name="t"></param>  
        public static void InsertXmlItem(T t)
        {
           

            string className = ReflectionUtils<T>.GetClassName(t);
            //if (!Directory.Exists(xmlPath + className + ".xml"))
            //{
            //    CreateXMLFile(t);
            //}

            XmlDocument xmldoc = new XmlDocument();
            //加载xml文件  
            try
            {
                xmldoc.Load(xmlPath + className + ".xml");
            }
            catch (Exception e)
            {

                Console.WriteLine(e.Message);
            }

            //判断 主键号是否有值 或者 主键已经存在  

            //Object o = ReflectionUtils<T>.GetTPropertyValue(t,primaryPropertyName);
            //if (o != null && IsPrimaryKeyUnique(xmldoc,className,o))
            //{
            //获取根节点  
            XmlNode root = xmldoc.DocumentElement;
            //创建子节点  
            XmlElement itemNode = xmldoc.CreateElement(className);

            PropertyInfo[] propertyInfos = ReflectionUtils<T>.GetPropertyInfos(t);
            foreach (PropertyInfo propertyInfo in propertyInfos)
            {
                string propertyName = propertyInfo.Name;
                string propertyValue = propertyInfo.GetValue(t,null) == null ? "" : propertyInfo.GetValue(t,null).ToString();
                XmlElement propertyNode = xmldoc.CreateElement(propertyName);
                propertyNode.InnerText = propertyValue;
                itemNode.AppendChild(propertyNode);
            }
            root.AppendChild(itemNode);
            xmldoc.Save(xmlPath + className + ".xml");
            //}
            //else
            //{
            //    throw new Exception("插入数据失败，插入的主键为空或者主键已经存在。");
            //}


        }

        /// <summary>  
        /// 批量插入对象  
        /// </summary>  
        /// <param name="list"></param>  
        public static void BatchInsertXmlItem(List<T> list)
        {
            string className = typeof(T).Name;
            XmlDocument xmldoc = new XmlDocument();
            //加载xml文件  
            try
            {
                xmldoc.Load(xmlPath + className + ".xml");
            }
            catch (Exception e)
            {

                Console.WriteLine(e.Message);
            }
            //获取根节点  
            XmlNode root = xmldoc.DocumentElement;

            foreach (T t in list)
            {
                //创建子节点  
                XmlElement itemNode = xmldoc.CreateElement(className);
                PropertyInfo[] propertyInfos = ReflectionUtils<T>.GetPropertyInfos(t);
                foreach (PropertyInfo propertyInfo in propertyInfos)
                {
                    string propertyName = propertyInfo.Name;
                    string propertyValue = propertyInfo.GetValue(t,null).ToString();
                    XmlElement propertyNode = xmldoc.CreateElement(propertyName);
                    propertyNode.InnerText = propertyValue;
                    itemNode.AppendChild(propertyNode);
                }
                root.AppendChild(itemNode);
            }

            xmldoc.Save(xmlPath + className + ".xml");
        }

        /// <summary>  
        /// 更新对象  
        /// </summary>  
        /// <param name="t"></param>  
        public static void UpdateXmlItem(T t)
        {
            string className = ReflectionUtils<T>.GetClassName(t);
            XmlDocument xmldoc = new XmlDocument();
            //加载xml文件  
            try
            {
                xmldoc.Load(xmlPath + className + ".xml");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            // 拼接 XML XPath 查询字符串   
            string xPathStr = "Root/" + className + "[" + primaryPropertyName + "='" + ReflectionUtils<T>.GetTPropertyValue(t,primaryPropertyName) + "']";
            // XPath 查询  
            XmlNodeList nodes = xmldoc.SelectNodes(xPathStr);
            if (nodes.Count > 0)
            {
                foreach (XmlNode xmlNode in nodes)
                {
                    XmlElement xmlElement = (XmlElement)xmlNode;
                    // 属性遍历  
                    PropertyInfo[] propertyInfos = ReflectionUtils<T>.GetPropertyInfos(t);
                    foreach (PropertyInfo propertyInfo in propertyInfos)
                    {
                        string propertyName = propertyInfo.Name;
                        string propertyValue = propertyInfo.GetValue(t,null).ToString();
                        // 更新  
                        xmlElement.SelectSingleNode(propertyName).InnerText = propertyValue;
                    }
                }
                // 保存  
                xmldoc.Save(xmlPath + className + ".xml");
            }
        }

        /// <summary>  
        /// 删除对象  
        /// </summary>  
        /// <param name="t"></param>  
        public static void DeleteXMLItem(T t)
        {
            string className = ReflectionUtils<T>.GetClassName(t);
            XmlDocument xmldoc = new XmlDocument();
            //加载xml文件  
            try
            {
                xmldoc.Load(xmlPath + className + ".xml");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            // 拼接 XML XPath 查询字符串   
            string xPathStr = "Root/" + className + "[" + primaryPropertyName + "='" + ReflectionUtils<T>.GetTPropertyValue(t,primaryPropertyName) + "']";
            // XPath 查询  
            XmlNodeList nodes = xmldoc.SelectNodes(xPathStr);
            if (nodes.Count > 0)
            {
                foreach (XmlNode xmlNode in nodes)
                {
                    xmlNode.ParentNode.RemoveChild(xmlNode);
                }
                xmldoc.Save(xmlPath + className + ".xml");
            }
        }

        /// <summary>  
        /// 获取所有对象  
        /// </summary>  
        /// <returns></returns>  
        public static List<T> GetList()
        {
            List<T> list = new List<T>();
            string className = typeof(T).Name;
            XmlDocument xmldoc = new XmlDocument();
            //加载xml文件  
            try
            {
                xmldoc.Load(xmlPath + className + ".xml");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            XmlNodeList nodeList = xmldoc.GetElementsByTagName(className);
            foreach (XmlNode xmlNode in nodeList)
            {
                T t = Activator.CreateInstance<T>();
                XmlElement xmlElement = (XmlElement)xmlNode;
                // 属性遍历  
                PropertyInfo[] propertyInfos = ReflectionUtils<T>.GetPropertyInfos(t);
                foreach (PropertyInfo propertyInfo in propertyInfos)
                {
                    string propertyName = propertyInfo.Name;
                    object nodeString= xmlElement.SelectSingleNode(propertyName).InnerText;
                    ReflectionUtils<T>.SetTPropertyValue(t,propertyName,nodeString);
                }
                list.Add(t);
            }
            return list;
        }

        /// <summary>  
        /// 多条件查询 查询数组为空，表示查询所有  
        /// </summary>  
        /// <param name="pName">属性名</param>  
        /// <param name="value">属性值</param>  
        /// <param name="isEqual">true 等值查询，false 模糊查询</param>  
        /// <returns></returns>  
        public static List<T> GetListByCondition(string[] pNames,string[] values,Boolean isEqual)
        {
            List<T> list = new List<T>();
            string className = typeof(T).Name;
            XmlDocument xmldoc = new XmlDocument();
            //加载xml文件  
            try
            {
                xmldoc.Load(xmlPath + className + ".xml");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            // 拼接 XML XPath 查询字符串  
            string condition = GetXPath(pNames,values,isEqual);
            string xPathStr = "Root/" + className + condition;

            // XPath 查询  
            XmlNodeList nodeList = xmldoc.SelectNodes(xPathStr);

            foreach (XmlNode xmlNode in nodeList)
            {
                T t = Activator.CreateInstance<T>();
                XmlElement xmlElement = (XmlElement)xmlNode;
                // 属性遍历  
                PropertyInfo[] propertyInfos = ReflectionUtils<T>.GetPropertyInfos(t);
                foreach (PropertyInfo propertyInfo in propertyInfos)
                {
                    string propertyName = propertyInfo.Name;
                    ReflectionUtils<T>.SetTPropertyValue(t,xmlElement.SelectSingleNode(propertyName).InnerText);
                }
                list.Add(t);
            }
            return list;
        }

 

        /// <summary>  
        /// 拼接 XPath 查询条件参数  
        /// 等值查询：string xPath = "users/user[username='huo' and password='123']";  
        /// 模糊查询：string xPath = "users/user[contains(username,'huo') and contains(password,'123')]";  
        /// </summary>  
        /// <param name="pNames"></param>  
        /// <param name="values"></param>  
        /// <returns></returns>  
        private static string GetXPath(string[] pNames,Boolean isEqual)
        {
            StringBuilder sb = new StringBuilder();
            //等值查询  
            if (isEqual)
            {
                //添加第一个元素  
                if (pNames.Length > 0)
                {
                    sb.Append("[");
                    sb.Append(pNames[0]);
                    sb.Append("='");
                    sb.Append(values[0]);
                    sb.Append("'");
                }
                //添加后续元素  
                if (pNames.Length > 1)
                {
                    for (int i = 1; i < pNames.Length; i++)
                    {
                        sb.Append(" and ");
                        sb.Append(pNames[i]);
                        sb.Append("='");
                        sb.Append(values[i]);
                        sb.Append("'");
                    }
                }
                //结尾加上 ]  
                if (sb.Length > 0)
                {
                    sb.Append("]");
                }
            }
            else   //模糊查询  
            {
                //添加第一个元素  
                if (pNames.Length > 0)
                {
                    sb.Append("[");
                    sb.Append("contains(");
                    sb.Append(pNames[0]);
                    sb.Append(",'");
                    sb.Append(values[0]);
                    sb.Append("')");
                }
                //添加后续元素  
                if (pNames.Length > 1)
                {
                    for (int i = 1; i < pNames.Length; i++)
                    {
                        sb.Append(" and ");
                        sb.Append("[");
                        sb.Append("contains(");
                        sb.Append(pNames[i]);
                        sb.Append(",'");
                        sb.Append(values[i]);
                        sb.Append("')");
                    }
                }
                //结尾加上 ]  
                if (sb.Length > 0)
                {
                    sb.Append("]");
                }
            }
            return sb.ToString();
        }

    }
}

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!