.NET 基礎 一步步 一幕幕[XML基礎操做]

XML可擴展標記語言，標準通用標記語言的子集，是一種用於標記電子文件使其具備結構性的標記語言。

什麼是XML，學他有什麼用？

優勢：容易讀懂，格式標準任何語言都內置了XML分析引擎，不用單獨進行文件分析引擎得編寫。

XML語法規範：標籤（Tag）、嵌套（Nest）、屬性。標籤要閉合，屬性值要用」」包圍，標籤能夠相互嵌套。

大小寫敏感。

XML樹，父節點、子節點、兄弟節點。

寫入一個XML文件

//一、建立一個XML文檔對象

            XmlDocument doc = new XmlDocument();

            //二、建立第一行描述信息

            XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "utf-8", null);

            //三、將建立的第一行數據添加到文檔中

            doc.AppendChild(dec);

            //四、給文檔添加根節點

            XmlElement books = doc.CreateElement("Books");

            //五、將根節點添加給文檔對象

            doc.AppendChild(books);

 

            //六、給根節點添加子節點

            XmlElement book1 = doc.CreateElement("Book");

            //將子節點book1添加到根節點下

            books.AppendChild(book1);

 

            //七、給book1添加子節點

            XmlElement bookName1 = doc.CreateElement("BookName");

            //八、設置標籤中顯示的文本

            bookName1.InnerText = "水滸傳";

            book1.AppendChild(bookName1);

 

            XmlElement author1 = doc.CreateElement("Author");

            author1.InnerText = "<authorName>匿名</authorName>";

            book1.AppendChild(author1);

 

            XmlElement price1 = doc.CreateElement("Price");

            price1.InnerXml = "<authorName>匿名</authorName>";

            book1.AppendChild(price1);

 

            XmlElement des1 = doc.CreateElement("Des");

            des1.InnerXml = "好看，頂！~！！！！";

            book1.AppendChild(des1);

 

            Console.WriteLine("保存成功");

            doc.Save("Book.xml");

演示結果：

<?xml version="1.0" encoding="utf-8" ?>

<Books>

  <Book>

    <BookName>水滸傳</BookName>

    <Author>XXX</Author>

    <Price>100RMB</Price>

    <Des>好看！！經典！！！！頂！！！！</Des>

  </Book>

  <Book>

    <BookName>三國演義</BookName>

    <Author>XXX</Author>

    <Price>200RMB</Price>

    <Des>好看，頂！！！！</Des>

  </Book>

</Books>

 

添加帶屬性的XML文檔

XmlDocument doc = new XmlDocument();

            XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "utf-8", null);

            doc.AppendChild(dec);

 

            XmlElement order = doc.CreateElement("Order");

            doc.AppendChild(order);

 

            XmlElement customerName = doc.CreateElement("CustomerName");

            customerName.InnerXml = "劉洋";

            order.AppendChild(customerName);

 

            XmlElement orderNumber = doc.CreateElement("OrderNumber");

            orderNumber.InnerXml = "10000";

            order.AppendChild(orderNumber);

 

            XmlElement items = doc.CreateElement("Items");

            order.AppendChild(items);

 

            XmlElement orderItem1 = doc.CreateElement("OrderItem");

            orderItem1.SetAttribute("Name", "碼錶");

            orderItem1.SetAttribute("Count", "100001");

            items.AppendChild(orderItem1);

 

            XmlElement orderItem2 = doc.CreateElement("OrderItem");

            orderItem2.SetAttribute("Name", "雨衣");

            orderItem2.SetAttribute("Count", "1");

            items.AppendChild(orderItem2);

            doc.Save("Order.xml");

 

文檔對象模型

對象實體：

Public class Student

    {

        public int Age { get; set; }

        public string Name { get; set; }

        public int ID { get; set; }

        public char Gender { get; set; }

    }

 

List<Student> list = new List<Student>();

            list.Add(new Student() { ID = 1, Name = "yhb", Gender = '男', Age = 30 });

            list.Add(new Student() { ID = 2, Name = "wl", Gender = '女', Age = 20 });

            list.Add(new Student() { ID = 3, Name = "劉德華", Gender = '男', Age = 50 });

            list.Add(new Student() { ID = 4, Name = "張學友", Gender = '男', Age = 60 });

            list.Add(new Student() { ID = 5, Name = "哥哥", Gender = '男', Age = -10 });

 

            XmlDocument doc = new XmlDocument();

            XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "utf-8", null);

 

            doc.AppendChild(dec);

 

            XmlElement person = doc.CreateElement("Person");

            doc.AppendChild(person);

 

            //經過循環List集合，得到全部對象 以節點的形式添加到XML文檔中

            for (int i = 0; i < list.Count; i++)

            {

                XmlElement student = doc.CreateElement("Student");

                student.SetAttribute("studentID", list[i].ID.ToString());

                XmlElement name = doc.CreateElement("Name");

                name.InnerXml = list[i].Name;

                XmlElement age = doc.CreateElement("Age");

                age.InnerXml = list[i].Age.ToString();

                XmlElement gender = doc.CreateElement("Gender");

                gender.InnerXml = list[i].Gender.ToString();

                //添加

                person.AppendChild(student);

                student.AppendChild(name);

                student.AppendChild(age);

                student.AppendChild(gender);

            }

            doc.Save("Student.xml");

  對xml文檔實現增刪改查

         //XMLDocument

           #region 對xml文檔實現追加的需求

           XmlDocument doc = new XmlDocument();

           //首先判斷xml文檔是否存在 若是存在 則追加  不然建立一個

           if (File.Exists("Student.xml"))

           {

               //加載進來

               doc.Load("Student.xml");

               //追加

               //得到根節點 給根節點添加子節點

               XmlElement person = doc.DocumentElement;

 

               XmlElement student = doc.CreateElement("Student");

               student.SetAttribute("studentID", "10");

               person.AppendChild(student);

 

               XmlElement name = doc.CreateElement("Name");

               name.InnerXml = "我是新來噠";

               student.AppendChild(name);

 

               XmlElement age = doc.CreateElement("Age");

               age.InnerXml = "18";

               student.AppendChild(age);

 

               XmlElement gender = doc.CreateElement("Gender");

               gender.InnerXml = "女";

               student.AppendChild(gender);

 

           }

           else

           {

               //不存在

               XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "utf-8", null);

               doc.AppendChild(dec);

               XmlElement person = doc.CreateElement("Person");

               doc.AppendChild(person);

               XmlElement student = doc.CreateElement("Student");

               student.SetAttribute("studentID", "110");

               person.AppendChild(student);

               XmlElement name = doc.CreateElement("Name");

               name.InnerXml = "張三三李思思";

               student.AppendChild(name);

               XmlElement age = doc.CreateElement("Age");

               age.InnerXml = "28";

               student.AppendChild(age);

 

               XmlElement gender = doc.CreateElement("Gender");

               gender.InnerXml = "男";

               student.AppendChild(gender);

           }

           doc.Save("Student.xml");

           Console.WriteLine("保存成功");

           #endregion

           #region 讀取XML文檔

           XmlDocument doc = new XmlDocument();

           doc.Load("OrDER.xml");

           仍是 先得到根節點

           XmlElement order = doc.DocumentElement;

           得到根節點下面的全部子節點

           XmlNodeList xnl = order.ChildNodes;

           foreach (XmlNode item in xnl)

           {

               Console.WriteLine(item.InnerText);

           }

           XmlElement items = order["Items"];

           XmlNodeList xnl2 = items.ChildNodes;

           foreach (XmlNode item in xnl2)

           {

               Console.WriteLine(item.Attributes["Name"].Value);

               Console.WriteLine(item.Attributes["Count"].Value);

               if (item.Attributes["Name"].Value == "手套")

               {

                   item.Attributes["Count"].Value = "新來噠";

               }

           }

           doc.Save("OrDER.xml");

           #endregion

           #region 使用XPath的方式來讀取XML文件

           XmlDocument doc = new XmlDocument();

           doc.Load("order.xml");

           //得到根節點

           XmlElement order = doc.DocumentElement;

           XmlNode xn = order.SelectSingleNode("/Order/Items/OrderItem[@Name='雨衣']");

           Console.WriteLine(xn.Attributes["Name"].Value);

           xn.Attributes["Count"].Value = "woshi new";

           doc.Save("order.xml");

           Console.WriteLine("保存成功");

           #endregion

           XmlDocument doc = new XmlDocument();

           doc.Load("order.xml");

           //doc.RemoveAll();不行 根節點不容許刪除

           XmlElement order = doc.DocumentElement;

           order.RemoveAll(); 移除根節點下的全部子節點

           XmlNode xn = order.SelectSingleNode("/Order/Items/OrderItem[@Name='雨衣']");

           //讓orderItem去刪除屬性

           XmlNode orderItem = order.SelectSingleNode("/Order/Items/OrderItem");

           //得到Items節點

           XmlNode items = order["Items"];//order.SelectSingleNode("/Order/Items");

           items.RemoveChild(xn); //移除當前節點

            //orderItem.RemoveAttributeNode(xn.Attributes["Count"]);

           xn.Attributes.RemoveNamedItem("Count");

           doc.Save("order.xml");

           Console.WriteLine("刪除成功");

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