xml 增删改查基础复习及干货分享（日后留用）

xml被设计用来传输和存储数据。（html被设计用来显示数据）

• xml指可扩展标记语言（Extensible Markup Language）
• xml是一种标记语言，很类似html
• xml的设计宗旨是传输数据，而非显示数据
• xml标签没有被预定义。您需要自行定义标签
• xml被设计为具有自我描述性
• xml是w3c的推荐标准

C#操作XML的基本操作：增删改查

demo示例代码：

<？xml version="1.0" encoding="utf-8">
<info>
   <userinfo>
     <name>花哥</name>
     <age>26</age>
     <email>921442206@qq.com</email>
     <website>51chiheng.com</website>
  </userinfo>
</info>

增加：

XmlDocument xmld = new XmlDocument();
xmld.Load(Server.MapPath("myfolder/userinfo.xml"));//加载xml文件 
XmlNode root = xmld.SelectSingleNode("info");//查找info根节点

 XmlElement xml0 = xmld.CreateElement("userinfo");
 xml0.SetAttribute("realname", "花**");

XmlElement xml1 = xmld.CreateElement("age");//创建一个age节点
xml1.InnerText ="26";
xml0.AppendChild(xml1);//添加

XmlElement xml2 = xmld.CreateElement("email");//创建emial节点
xml2.InnerText ="921442206@qq.com";
xml0.AppendChild(xml2);//添加

XmlElement xml3 = xmld.CreateElement("website");//创建一个website节点
xml3.InnerText = "51chiheng.com";
xml0.AppendChild(xml3);//添加

root.AppendChild(xml0);
 xmld.Save(Server.MapPath("myfolder/userinfo.xml"));

删除操作：

XmlDocument xmld = new XmlDocument();

xmld.Load(Server.MapPath("myfolder/userinfo.xml"));

XmlNodeList list = xmld.SelectSingleNode("info").ChildNodes;

foreach (XmlNode var in list)
   {
      XmlElement xmle = (XmlElement)var;
      if (xmle.GetAttribute("readname") == "花**")
       {
           xmle.RemoveAll();
           xmld.Save(Server.MapPath("myfolder/userinfo.xml"));//删除后记得一定要保存
           Page.ClientScript.RegisterStartupScript(GetType(), "", "alert('删除成功!!');", true);
            }
            else
            {
                Page.ClientScript.RegisterStartupScript(GetType(), "", "alert('删除失败!!');", true);
            }
       }

修改操作：

XmlDocument xmld = new XmlDocument();  xmld.Load(Server.MapPath("App_Code/Message.xml"));
 XmlNodeList list = xmld.SelectSingleNode("messageList").ChildNodes;

 foreach (XmlNode xmln in list)
 {
   XmlElement xmle = (XmlElement)xmln;//格式转换
   if ("花**".Equals(xmle.GetAttribute("readname")))
   {
     xmle.ChildNodes[0].InnerText = "111";
     xmle.ChildNodes[1].InnerText = "222";
     xmle.ChildNodes[2].InnerText = "333";
     xmle.ChildNodes[3].InnerText = "444";
     xmld.Save(Server.MapPath("myfolder/userinfo.xml"));
     Page.ClientScript.RegisterStartupScript(this.GetType(), "", "alert('修改成功！！！');location.href='index.aspx'",true);
   }
 }

查询操作：

//下面的代码开始是用页面编码的方式实现的
XmlDocument xmld = new XmlDocument();//构建xml文档
xmld.Load(Server.MapPath("App_Code/Message.xml"));//加载

XmlNodeList list = xmld.SelectSingleNode("messageList").ChildNodes;//获取子节点
 if (list!=null)
    {
       foreach (XmlNode node in list)
       {
         XmlElement xmle = (XmlElement)node;//转换
         //todo.... 
        }
     }

最后分享一点干货，聪明的程序员会学会站在巨人的肩膀上去眺望远方，而不是一直闷头苦干的造轮胎,感谢苏飞大神！

/// <summary>
/// 好东西分享： xml帮助类大全
/// 类说明：【感谢苏飞大侠分享的好东西】
/// </summary>
using System;
using System.Data;
using System.IO;
using System.Xml;
 
namespace DotNet.Utilities
{
    public class XMLProcess
    {
        #region 构造函数
        public XMLProcess()
        { }
 
        public XMLProcess(string strPath)
        {
            this._XMLPath = strPath;
        }
        #endregion
 
        #region 公有属性
        private string _XMLPath;
        public string XMLPath
        {
            get { return this._XMLPath; }
        }
        #endregion
 
        #region 私有方法
        /// <summary>
        /// 导入XML文件
        /// </summary>
        /// <param name="XMLPath">XML文件路径</param>
        private XmlDocument XMLLoad()
        {
            string XMLFile = XMLPath;
            XmlDocument xmldoc = new XmlDocument();
            try
            {
                string filename = AppDomain.CurrentDomain.BaseDirectory.ToString() + XMLFile;
                if (File.Exists(filename)) xmldoc.Load(filename);
            }
            catch (Exception e)
            { }
            return xmldoc;
        }
 
        /// <summary>
        /// 导入XML文件
        /// </summary>
        /// <param name="XMLPath">XML文件路径</param>
        private static XmlDocument XMLLoad(string strPath)
        {
            XmlDocument xmldoc = new XmlDocument();
            try
            {
                string filename = AppDomain.CurrentDomain.BaseDirectory.ToString() + strPath;
                if (File.Exists(filename)) xmldoc.Load(filename);
            }
            catch (Exception e)
            { }
            return xmldoc;
        }
 
        /// <summary>
        /// 返回完整路径
        /// </summary>
        /// <param name="strPath">Xml的路径</param>
        private static string GetXmlFullPath(string strPath)
        {
            if (strPath.IndexOf(":") > 0)
            {
                return strPath;
            }
            else
            {
                return System.Web.HttpContext.Current.Server.MapPath(strPath);
            }
        }
        #endregion
 
        #region 读取数据
        /// <summary>
        /// 读取指定节点的数据
        /// </summary>
        /// <param name="node">节点</param>
        /// 使用示列:
        /// XMLProsess.Read("/Node", "")
        /// XMLProsess.Read("/Node/Element[@Attribute='Name']")
        public string Read(string node)
        {
            string value = "";
            try
            {
                XmlDocument doc = XMLLoad();
                XmlNode xn = doc.SelectSingleNode(node);
                value = xn.InnerText;
            }
            catch { }
            return value;
        }
 
        /// <summary>
        /// 读取指定路径和节点的串联值
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时返回该属性值，否则返回串联值</param>
        /// 使用示列:
        /// XMLProsess.Read(path, "/Node", "")
        /// XMLProsess.Read(path, "/Node/Element[@Attribute='Name']")
        public static string Read(string path, string node)
        {
            string value = "";
            try
            {
                XmlDocument doc = XMLLoad(path);
                XmlNode xn = doc.SelectSingleNode(node);
                value = xn.InnerText;
            }
            catch { }
            return value;
        }
 
        /// <summary>
        /// 读取指定路径和节点的属性值
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时返回该属性值，否则返回串联值</param>
        /// 使用示列:
        /// XMLProsess.Read(path, "/Node", "")
        /// XMLProsess.Read(path, "/Node/Element[@Attribute='Name']", "Attribute")
        public static string Read(string path, string node, string attribute)
        {
            string value = "";
            try
            {
                XmlDocument doc = XMLLoad(path);
                XmlNode xn = doc.SelectSingleNode(node);
                value = (attribute.Equals("") ? xn.InnerText : xn.Attributes[attribute].Value);
            }
            catch { }
            return value;
        }
 
        /// <summary>
        /// 获取某一节点的所有孩子节点的值
        /// </summary>
        /// <param name="node">要查询的节点</param>
        public string[] ReadAllChildallValue(string node)
        {
            int i = 0;
            string[] str = { };
            XmlDocument doc = XMLLoad();
            XmlNode xn = doc.SelectSingleNode(node);
            XmlNodeList nodelist = xn.ChildNodes;  //得到该节点的子节点
            if (nodelist.Count > 0)
            {
                str = new string[nodelist.Count];
                foreach (XmlElement el in nodelist)//读元素值
                {
                    str[i] = el.Value;
                    i++;
                }
            }
            return str;
        }
 
        /// <summary>
        /// 获取某一节点的所有孩子节点的值
        /// </summary>
        /// <param name="node">要查询的节点</param>
        public XmlNodeList ReadAllChild(string node)
        {
            XmlDocument doc = XMLLoad();
            XmlNode xn = doc.SelectSingleNode(node);
            XmlNodeList nodelist = xn.ChildNodes;  //得到该节点的子节点
            return nodelist;
        }
 
        /// <summary> 
        /// 读取XML返回经排序或筛选后的DataView
        /// </summary>
        /// <param name="strWhere">筛选条件，如:"name='kgdiwss'"</param>
        /// <param name="strSort"> 排序条件，如:"Id desc"</param>
        public DataView GetDataViewByXml(string strWhere, string strSort)
        {
            try
            {
                string XMLFile = this.XMLPath;
                string filename = AppDomain.CurrentDomain.BaseDirectory.ToString() + XMLFile;
                DataSet ds = new DataSet();
                ds.ReadXml(filename);
                DataView dv = new DataView(ds.Tables[0]); //创建DataView来完成排序或筛选操作  
                if (strSort != null)
                {
                    dv.Sort = strSort; //对DataView中的记录进行排序
                }
                if (strWhere != null)
                {
                    dv.RowFilter = strWhere; //对DataView中的记录进行筛选，找到我们想要的记录
                }
                return dv;
            }
            catch (Exception)
            {
                return null;
            }
        }
 
        /// <summary>
        /// 读取XML返回DataSet
        /// </summary>
        /// <param name="strXmlPath">XML文件相对路径</param>
        public DataSet GetDataSetByXml(string strXmlPath)
        {
            try
            {
                DataSet ds = new DataSet();
                ds.ReadXml(GetXmlFullPath(strXmlPath));
                if (ds.Tables.Count > 0)
                {
                    return ds;
                }
                return null;
            }
            catch (Exception)
            {
                return null;
            }
        }
        #endregion
 
        #region 插入数据
        /// <summary>
        /// 插入数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="element">元素名，非空时插入新元素，否则在该元素中插入属性</param>
        /// <param name="attribute">属性名，非空时插入该元素属性值，否则插入元素值</param>
        /// <param name="value">值</param>
        /// 使用示列:
        /// XMLProsess.Insert(path, "/Node", "Element", "", "Value")
        /// XMLProsess.Insert(path, "/Node", "Element", "Attribute", "Value")
        /// XMLProsess.Insert(path, "/Node", "", "Attribute", "Value")
        public static void Insert(string path, string node, string element, string attribute, string value)
        {
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
                XmlNode xn = doc.SelectSingleNode(node);
                if (element.Equals(""))
                {
                    if (!attribute.Equals(""))
                    {
                        XmlElement xe = (XmlElement)xn;
                        xe.SetAttribute(attribute, value);
                    }
                }
                else
                {
                    XmlElement xe = doc.CreateElement(element);
                    if (attribute.Equals(""))
                        xe.InnerText = value;
                    else
                        xe.SetAttribute(attribute, value);
                    xn.AppendChild(xe);
                }
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
            }
            catch { }
        }
 
        /// <summary>
        /// 插入数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="element">元素名，非空时插入新元素，否则在该元素中插入属性</param>
        /// <param name="strList">由XML属性名和值组成的二维数组</param>
        public static void Insert(string path, string node, string element, string[][] strList)
        {
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
                XmlNode xn = doc.SelectSingleNode(node);
                XmlElement xe = doc.CreateElement(element);
                string strAttribute = "";
                string strValue = "";
                for (int i = 0; i < strList.Length; i++)
                {
                    for (int j = 0; j < strList[i].Length; j++)
                    {
                        if (j == 0)
                            strAttribute = strList[i][j];
                        else
                            strValue = strList[i][j];
                    }
                    if (strAttribute.Equals(""))
                        xe.InnerText = strValue;
                    else
                        xe.SetAttribute(strAttribute, strValue);
                }
                xn.AppendChild(xe);
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
            }
            catch { }
        }
 
        /// <summary>
        /// 插入一行数据
        /// </summary>
        /// <param name="strXmlPath">XML文件相对路径</param>
        /// <param name="Columns">要插入行的列名数组，如：string[] Columns = {"name","IsMarried"};</param>
        /// <param name="ColumnValue">要插入行每列的值数组，如：string[] ColumnValue={"XML大全","false"};</param>
        /// <returns>成功返回true,否则返回false</returns>
        public static bool WriteXmlByDataSet(string strXmlPath, string[] Columns, string[] ColumnValue)
        {
            try
            {
                //根据传入的XML路径得到.XSD的路径，两个文件放在同一个目录下
                string strXsdPath = strXmlPath.Substring(0, strXmlPath.IndexOf(".")) + ".xsd";
                DataSet ds = new DataSet();
                ds.ReadXmlSchema(GetXmlFullPath(strXsdPath)); //读XML架构，关系到列的数据类型
                ds.ReadXml(GetXmlFullPath(strXmlPath));
                DataTable dt = ds.Tables[0];
                DataRow newRow = dt.NewRow();                 //在原来的表格基础上创建新行
                for (int i = 0; i < Columns.Length; i++)      //循环给一行中的各个列赋值
                {
                    newRow[Columns[i]] = ColumnValue[i];
                }
                dt.Rows.Add(newRow);
                dt.AcceptChanges();
                ds.AcceptChanges();
                ds.WriteXml(GetXmlFullPath(strXmlPath));
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }
        #endregion
 
        #region 修改数据
        /// <summary>
        /// 修改指定节点的数据
        /// </summary>
        /// <param name="node">节点</param>
        /// <param name="value">值</param>
        public void Update(string node, string value)
        {
            try
            {
                XmlDocument doc = XMLLoad();
                XmlNode xn = doc.SelectSingleNode(node);
                xn.InnerText = value;
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + XMLPath);
            }
            catch { }
        }
 
        /// <summary>
        /// 修改指定节点的数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="value">值</param>
        /// 使用示列:
        /// XMLProsess.Insert(path, "/Node","Value")
        /// XMLProsess.Insert(path, "/Node","Value")
        public static void Update(string path, string node, string value)
        {
            try
            {
                XmlDocument doc = XMLLoad(path);
                XmlNode xn = doc.SelectSingleNode(node);
                xn.InnerText = value;
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
            }
            catch { }
        }
 
        /// <summary>
        /// 修改指定节点的属性值(静态)
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时修改该节点属性值，否则修改节点值</param>
        /// <param name="value">值</param>
        /// 使用示列:
        /// XMLProsess.Insert(path, "/Node", "", "Value")
        /// XMLProsess.Insert(path, "/Node", "Attribute", "Value")
        public static void Update(string path, string node, string attribute, string value)
        {
            try
            {
                XmlDocument doc = XMLLoad(path);
                XmlNode xn = doc.SelectSingleNode(node);
                XmlElement xe = (XmlElement)xn;
                if (attribute.Equals(""))
                    xe.InnerText = value;
                else
                    xe.SetAttribute(attribute, value);
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
            }
            catch { }
        }
 
        /// <summary>
        /// 更改符合条件的一条记录
        /// </summary>
        /// <param name="strXmlPath">XML文件路径</param>
        /// <param name="Columns">列名数组</param>
        /// <param name="ColumnValue">列值数组</param>
        /// <param name="strWhereColumnName">条件列名</param>
        /// <param name="strWhereColumnValue">条件列值</param>
        public static bool UpdateXmlRow(string strXmlPath, string[] Columns, string[] ColumnValue, string strWhereColumnName, string strWhereColumnValue)
        {
            try
            {
                string strXsdPath = strXmlPath.Substring(0, strXmlPath.IndexOf(".")) + ".xsd";
                DataSet ds = new DataSet();
                ds.ReadXmlSchema(GetXmlFullPath(strXsdPath));//读XML架构，关系到列的数据类型
                ds.ReadXml(GetXmlFullPath(strXmlPath));
 
                //先判断行数
                if (ds.Tables[0].Rows.Count > 0)
                {
                    for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                    {
                        //如果当前记录为符合Where条件的记录
                        if (ds.Tables[0].Rows[i][strWhereColumnName].ToString().Trim().Equals(strWhereColumnValue))
                        {
                            //循环给找到行的各列赋新值
                            for (int j = 0; j < Columns.Length; j++)
                            {
                                ds.Tables[0].Rows[i][Columns[j]] = ColumnValue[j];
                            }
                            ds.AcceptChanges();                     //更新DataSet
                            ds.WriteXml(GetXmlFullPath(strXmlPath));//重新写入XML文件
                            return true;
                        }
                    }
 
                }
                return false;
            }
            catch (Exception)
            {
                return false;
            }
        }
        #endregion
 
        #region 删除数据
        /// <summary>
        /// 删除节点值
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时删除该节点属性值，否则删除节点值</param>
        /// <param name="value">值</param>
        /// 使用示列:
        /// XMLProsess.Delete(path, "/Node", "")
        /// XMLProsess.Delete(path, "/Node", "Attribute")
        public static void Delete(string path, string node)
        {
            try
            {
                XmlDocument doc = XMLLoad(path);
                XmlNode xn = doc.SelectSingleNode(node);
                xn.ParentNode.RemoveChild(xn);
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
            }
            catch { }
        }
 
        /// <summary>
        /// 删除数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时删除该节点属性值，否则删除节点值</param>
        /// <param name="value">值</param>
        /// 使用示列:
        /// XMLProsess.Delete(path, "/Node", "")
        /// XMLProsess.Delete(path, "/Node", "Attribute")
        public static void Delete(string path, string node, string attribute)
        {
            try
            {
                XmlDocument doc = XMLLoad(path);
                XmlNode xn = doc.SelectSingleNode(node);
                XmlElement xe = (XmlElement)xn;
                if (attribute.Equals(""))
                    xn.ParentNode.RemoveChild(xn);
                else
                    xe.RemoveAttribute(attribute);
                doc.Save(AppDomain.CurrentDomain.BaseDirectory.ToString() + path);
            }
            catch { }
        }
 
        /// <summary>
        /// 删除所有行
        /// </summary>
        /// <param name="strXmlPath">XML路径</param>
        public static bool DeleteXmlAllRows(string strXmlPath)
        {
            try
            {
                DataSet ds = new DataSet();
                ds.ReadXml(GetXmlFullPath(strXmlPath));
                if (ds.Tables[0].Rows.Count > 0)
                {
                    ds.Tables[0].Rows.Clear();
                }
                ds.WriteXml(GetXmlFullPath(strXmlPath));
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }
 
        /// <summary>
        /// 通过删除DataSet中指定索引行，重写XML以实现删除指定行
        /// </summary>
        /// <param name="iDeleteRow">要删除的行在DataSet中的Index值</param>
        public static bool DeleteXmlRowByIndex(string strXmlPath, int iDeleteRow)
        {
            try
            {
                DataSet ds = new DataSet();
                ds.ReadXml(GetXmlFullPath(strXmlPath));
                if (ds.Tables[0].Rows.Count > 0)
                {
                    ds.Tables[0].Rows[iDeleteRow].Delete();
                }
                ds.WriteXml(GetXmlFullPath(strXmlPath));
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }
 
        /// <summary>
        /// 删除指定列中指定值的行
        /// </summary>
        /// <param name="strXmlPath">XML相对路径</param>
        /// <param name="strColumn">列名</param>
        /// <param name="ColumnValue">指定值</param>
        public static bool DeleteXmlRows(string strXmlPath, string strColumn, string[] ColumnValue)
        {
            try
            {
                DataSet ds = new DataSet();
                ds.ReadXml(GetXmlFullPath(strXmlPath));
                if (ds.Tables[0].Rows.Count > 0)
                {
                    //判断行多还是删除的值多，多的for循环放在里面
                    if (ColumnValue.Length > ds.Tables[0].Rows.Count)
                    {
                        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                        {
                            for (int j = 0; j < ColumnValue.Length; j++)
                            {
                                if (ds.Tables[0].Rows[i][strColumn].ToString().Trim().Equals(ColumnValue[j]))
                                {
                                    ds.Tables[0].Rows[i].Delete();
                                }
                            }
                        }
                    }
                    else
                    {
                        for (int j = 0; j < ColumnValue.Length; j++)
                        {
                            for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                            {
                                if (ds.Tables[0].Rows[i][strColumn].ToString().Trim().Equals(ColumnValue[j]))
                                {
                                    ds.Tables[0].Rows[i].Delete();
                                }
                            }
                        }
                    }
                    ds.WriteXml(GetXmlFullPath(strXmlPath));
                }
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }
        #endregion
    }
}