详细介绍xml的使用方法总结

1、 认识xml

可扩展标记语言，一种用于标记电子文档使其具有结果性的标记语言，它可以用来标记数据、定义数据类型，是一种允许用户对自己的标记语言进行定义的源语言。

2、 和超文本标记语言区别

2.1 html不一定需要成对出现，xml则一定需要成对出现。

2.2 html 不区分大小写，但是xml区分。

3、对xml文档增删改查

//声明一个XmlDocument空对象
       protected XmlDocument XmlDoc = new XmlDocument();
       /// <summary>
       /// 构造函数，导入xml文件
       /// </summary>
       /// <param name="path"></param>
       public XmlHelper(string path)
       {
           try
           {
               XmlDoc.Load(path);
           }
           catch (Exception ex)
           {
               throw ex;
           }
       }
       /// <summary>
       /// 保存文件
       /// </summary>
       /// <param name="path"></param>
       public void SaveXml(string path)
       {
           try
           {
               XmlDoc.Save(path);
           }
           catch (System.Exception ex)
           {
               throw ex;
           }
       }

/// <summary>
       /// 获取节点的子节点的内容
       /// </summary>
       /// <param name="path"></param>
       /// <param name="rootNode"></param>
       /// <param name="attributeName"></param>
       /// <returns></returns>
       public string GetNodeChildAttribute(string path, string rootNode, string attributeName)
       {
           XmlNode xn = XmlDoc.SelectSingleNode(rootNode);
           StringBuilder sb = new StringBuilder();
           XmlNodeList xnl = xn.ChildNodes;
 
           foreach (XmlNode xnf in xnl)
           {
               XmlElement xe = (XmlElement)xnf;
               XmlNodeList xnf1 = xe.ChildNodes;
               foreach (XmlNode xn2 in xnf1)
               {
                   if (xn2.Name == attributeName)
                   {
                       sb.Append(xn2.InnerText);//显示子节点点文本
                   }
               }
           }
           return sb.ToString();
       }

/// <summary>
        /// 获取节点的属性值
        /// </summary>
        /// <param name="path">xml路径</param>
        /// <param name="rootNode">根节点名称</param>
        /// <param name="attributeName">属性名称</param>
        /// <returns></returns>
        public string GetNodeAttribute(string path, string rootNode, string attributeName)
        {
            try
            {
                XmlNode xn = XmlDoc.SelectSingleNode(rootNode);
                XmlNodeList xnl = xn.ChildNodes;
                StringBuilder sb = new StringBuilder();
                foreach (XmlNode xnf in xnl)
                {
                    XmlElement xe = (XmlElement)xnf;
                    sb.Append(xe.GetAttribute(attributeName));
                }
                return sb.ToString();
            }
            catch (Exception)
            {
 
                throw;
            }
        }

/// <summary>
       /// 删除节点/节点属性
       /// </summary>
       /// <param name="path">xml文件地址</param>
       /// <param name="rootNode">根节点名称</param>
       /// <param name="delNode">要删除的节点</param>
       /// <param name="attributeName">节点属性</param>
       /// <param name="attributeValue">属性值</param>
       public void DeleteNode(string path, string rootNode, string attributeName, string attributeValue)
       {
           try
           {
               XmlNodeList xnl = XmlDoc.SelectSingleNode(rootNode).ChildNodes;
               foreach (XmlNode xn in xnl)
               {
                   XmlElement xe = (XmlElement)xn;
                   if (xe.GetAttribute(attributeName) == attributeValue)
                   {
                       //xe.RemoveAttribute(attributeName);//删除属性
                       xe.RemoveAll();//删除该节点的全部内容
                   }
               }
               SaveXml(path);
           }
           catch (Exception)
           {
 
               throw;
           }
       }

/// <summary>
       /// 修改节点的子节点内容
       /// </summary>
       /// <param name="path">xml文件路径</param>
       /// <param name="rootNode">根节点名称</param>
       /// <param name="attributeName">节点的子节点名称</param>
       /// <param name="attributeOldValue">节点的子节点原始内容</param>
       /// <param name="attributeNewValue">节点的子节点新内容</param>
       public void UpdateChildNodeAttribute(string path, string rootNode, string attributeName,string attributeOldValue, string attributeNewValue)
       {
           try
           {
               XmlNodeList nodeList = XmlDoc.SelectSingleNode(rootNode).ChildNodes;//获取根节点的所有子节点
               foreach (XmlNode xn in nodeList)//遍历所有子节点
               {
                   XmlElement xe = (XmlElement)xn;//将子节点类型转换为XmlElement类型
                   if (string.IsNullOrEmpty(attributeName) || string.IsNullOrEmpty(attributeOldValue))
                   {
                       return;
                   }
                   else
                   {
                       XmlNodeList nls = xe.ChildNodes;
                       if (nls != null && nls.Count > 0)
                       {
                           foreach (XmlNode xn1 in nls)//遍历
                           {
                               XmlElement xe2 = (XmlElement)xn1;//转换类型
                               if (xe2.InnerText == attributeOldValue)//如果找到
                               {
                                   xe2.InnerText = attributeNewValue;//则修改
                                   break;//找到退出来就可以了
                               }
                           }
                       }
                   }
               }
               SaveXml(path);
           }
           catch (Exception)
           {
 
               throw;
           }
       }

/// <summary>
        /// 修改节点属性值操作
        /// </summary>
        /// <param name="path">xml文件路径</param>
        /// <param name="rootNode">根节点名称，如：bookstore</param>
        /// <param name="attributeName">节点属性名</param>
        /// <param name="attributeOldValue">节点属性原来值</param>
        /// <param name="attributeNewValue">节点属性修改后的值</param>
        public void UpdateNodeAttribute(string path, string rootNode, string attributeName, string attributeOldValue, string attributeNewValue)
        {
            try
            {
                XmlNodeList nodeList = XmlDoc.SelectSingleNode(rootNode).ChildNodes;//获取根节点的所有子节点
                foreach (XmlNode xn in nodeList)//遍历所有子节点
                {
                    XmlElement xe = (XmlElement)xn;//将子节点类型专程xmlelement类型
                    if (string.IsNullOrEmpty(attributeName) || string.IsNullOrEmpty(attributeOldValue))
                    {
                        return;
                    }
                    else
                    {
                        if (xe.GetAttribute(attributeName) == attributeOldValue)
                        {
                            xe.SetAttribute(attributeName, attributeNewValue);
                        }
                    }
                }
                SaveXml(path);
            }
            catch (Exception)
            {
 
                throw;
            }
        }

/// <summary>
        /// 插入节点操作
        /// </summary>
        /// <param name="path">xml文件路径</param>
        /// <param name="rootNode">根节点名称，如：bookstore</param>
        /// <param name="node">节点名称，如：book</param>
        /// <param name="nodeAttributes">节点的属性-属性值集合</param>
        /// <param name="childAttributes">节点子节点名称-内容</param>
        public void InsertNode(string path, string rootNode, string node, Dictionary
        <string, string> nodeAttributes, Dictionary<string, string> childAttributes)
        {
            try
            {
                XmlNode root = XmlDoc.SelectSingleNode(rootNode);//找到根节点bookstore
                XmlElement xe1 = XmlDoc.CreateElement(node);//创建子节点book
                if (nodeAttributes != null && nodeAttributes.Count > 0)
                {
                    foreach (var n in nodeAttributes)
                    {
                        xe1.SetAttribute(n.Key, n.Value);
                    }
                }
                if (childAttributes != null && childAttributes.Count > 0)
                {
                    XmlElement xesub1;
                    foreach (var n in childAttributes)
                    {
                        xesub1 = XmlDoc.CreateElement(n.Key);
                        xesub1.InnerText = n.Value;
                        xe1.AppendChild(xesub1);//添加到<book>节点中
                    }
                }
                root.AppendChild(xe1);
                SaveXml(path);
            }
            catch (Exception)
            {
 
                throw;
            }
        }

调用：

string path = Server.MapPath("Books.xml");
           XmlHelper xHelper = new XmlHelper(path);
           /*插入*/
           //Dictionary<string, string> dc1 = new Dictionary<string, string>();
           //dc1.Add("genre", "李赞红");
           //dc1.Add("ISBN", "2-3631-4");
           //Dictionary<strin插入g, string> dc2 = new Dictionary<string, string>();
           //dc2.Add("title", "CS从入门到精通");
           //dc2.Add("author", "候捷");
           //dc2.Add("price", "58.3");
           //xHelper.InsertNode(path, "bookstore", "book", dc1, dc2);
 
           /*修改*/
           //xHelper.UpdateNodeAttribute(path, "bookstore", "genre", "李赞红", "李");
           //xHelper.UpdateChildNodeAttribute(path, "bookstore", "title", "CS从入门到精通", "cs");
 
           /*删除节点*/
           //xHelper.DeleteNode(path, "bookstore", "genre", "李");
 
           //Response.Write(xHelper.GetNodeAttribute(path, "bookstore", "genre"));
           //Response.Write(xHelper.GetNodeChildAttribute(path, "bookstore", "price"));

4、通过xml数据绑定

xml转DataTable

public DataTable XmlToData(string path, string rootNode, params string[] columns)
       {
           DataTable dt = new DataTable();
           XmlNodeList xn = XmlDoc.SelectSingleNode(rootNode).ChildNodes;
           try
           {
               if (columns.Length > 0)
               {
                   DataColumn dc;
                   for (int i = 0; i < columns.Length; i++)
                   {
                       dc = new DataColumn(columns[i]);
                       dt.Columns.Add(dc);
                   }
                   foreach (XmlNode xnf in xn)
                   {
                       XmlElement xe = (XmlElement)xnf;
                       XmlNodeList xnf1 = xe.ChildNodes;
                       int i = 0;
                       DataRow dr = dt.NewRow();
                       foreach (XmlNode xn2 in xnf1)
                       {
                           dr[i] = xn2.InnerText;
                           i++;
                       }
                       dt.Rows.Add(dr);
                   }
               }
           }
           catch (Exception)
           {
 
               throw;
           }
           return dt;
 
       }

调用：

//string[] arr = { "title", "author", "price" };
           //GridView1.DataSource = xHelper.XmlToData(path, "bookstore", arr);
           //GridView1.DataBind();

DataTable转xml

/*datatable转xml*/
       public  string DataTableToXml(DataTable dt)
       {
           if (dt != null)
           {
               MemoryStream ms = null;
               XmlTextWriter XmlWt = null;
               try
               {
                   ms = new MemoryStream();
                   //根据ms实例化XmlWt
                   XmlWt = new XmlTextWriter(ms, Encoding.Unicode);
                   //获取ds中的数据
                   dt.WriteXml(XmlWt);
                   int count = (int)ms.Length;
                   byte[] temp = new byte[count];
                   ms.Seek(0, SeekOrigin.Begin);
                   ms.Read(temp, 0, count);
                   //返回Unicode编码的文本
                   UnicodeEncoding ucode = new UnicodeEncoding();
                   string returnValue = ucode.GetString(temp).Trim();
                   return returnValue;
               }
               catch (System.Exception ex)
               {
                   throw ex;
               }
               finally
               {
                   //释放资源
                   if (XmlWt != null)
                   {
                       XmlWt.Close();
                       ms.Close();
                       ms.Dispose();
                   }
               }
           }
           else
           {
               return "";
           }
       }

调用：

//bool s = xHelper.CDataToXmlFile(xHelper.XmlToData(path, "bookstore", arr), "Bookss.xml","book");

5、xml序列化反序列化

[Serializable]
   public class Person
   {
       public string Name { get; set; }
       public int Age { get; set; }
   }

public class CXmlSerializer<T> where T : new()
    {
        private static XmlSerializer _Serializer = new XmlSerializer(typeof(T));
 
        public static string Serialize(T t)
        {
            string s = "";
            using (MemoryStream ms = new MemoryStream())
            {
                _Serializer.Serialize(ms, t);
                s = System.Text.UTF8Encoding.UTF8.GetString(ms.ToArray());
            }
            return s;
        }
 
        public static T Deserialize(string s)
        {
            T t;
            using (MemoryStream ms = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(s)))
            {
                t = (T)_Serializer.Deserialize(ms);
            }
            return t;
        }
    }

调用：

List<Person> list = new List<Person> { new Person { Name = "Xuj", Age = 20 }, new Person { Name = "duj", Age = 20 }, new Person { Name = "fuj", Age = 20 } };
            string s = CXmlSerializer<List<Person>>.Serialize(list);

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