C#中用XmlDocument对象获取XML文件中的节点值

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最新推荐文章于 2025-03-28 10:17:55 发布

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本文介绍如何在C#中利用XmlDocument类读取XML文件，并获取特定节点的值。通过实例演示了加载XML文件、指定编码、处理空值以及字符串操作的方法。

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C#中用XmlDocument对象获取XML文件中的节点值

XmlDocument是表示DOM的类。
1.加载XML文档：使用load()方法加载XML文档；
2.读取节点：使用GetElementById()、getElementsByTagName_r()方法根据ID或标签名读取节点；
3.查找节点：使用SelectSingleNode(string search)方法通过XPath查找节点；
4.插入节点：使用createElement_x()方法创建节点，AppendChild()方法添加新节点；
5.创建文档：通过XmlDeclaration对象新建声明节点，其他同插入节点。
xml文件:
<?xml version="1.0" encoding="utf-8" ?>
<bookstore>
<book>
<title lang="eng">Harry Potter</title>
<price>29.99</price>
</book>
<book>
<title lang="eng">Learning XML</title>
<price>39.98</price>
</book>
<bookstore>
<title lang="eng">Learning C#</title>
<price>55.23</price>
</bookstore>
<item name="1">第一个item</item>
<item name="2">
<item name="1">这个结点(1)</item>
<item name="2">这个结点(2)</item>
<book>
<title lang="cn">Learning C</title>
<price>60.95</price>
</book>
</item>
</bookstore>
XmlDocument xdoc = new XmlDocument();
xdoc.Load(Server.MapPath("books.xml"));
XmlNodeList xnl = xdoc.SelectNodes("/bookstore/book");
string nodeTempStr = "";
foreach (XmlNode node in xnl)
{
nodeTempStr = node.InnerText;
node ......

实例：处理books.xml文档

TestXmlDocument.cs:

001. using System;

002. using System.Xml;

003.

004. namespace Magci.Test.XML.TestXmlDocment

005. {

006. class Program

007. {

008. private static XmlDocument doc;

009.

010. static void Main(string[] args)

011. {

012. doc = new XmlDocument();

013. //加载XML文档

014. doc.Load(@"..\..\books.xml");

015. DisplayTitle();

016. SearchByTitle("The Gorgias");

017. Insert();

018. CreateDoc();

019.

020. Console.ReadLine();

021. }

022.

023. //遍历节点

024. public static void DisplayTitle()

025. {

026. XmlNodeList nodes = doc.getElementsByTagName_r("title");

027. Console.WriteLine("Title:");

028. foreach (XmlNode node in nodes)

029. {

030. Console.WriteLine(node.InnerText);

031. }

032. }

033.

034. //根据title查找

035. public static void SearchByTitle(string title)

036. {

037. string search = "bookstore/book[title='" + title + "']";

038. XmlNode foundNode = doc.SelectSingleNode(search);

039. Console.WriteLine("\nSearch by title:");

040. if (foundNode != null)

041. {

042. Console.WriteLine(foundNode.InnerText);

043. }

044. else

045. {

046. Console.WriteLine("Not Found!");

047. }

048. }

049.

050. //插入节点

051. public static void Insert()

052. {

053. //创建book元素

054. XmlElement newBook = doc.createElement_x("book");

055. newBook.SetAttribute("genre", "MyStery");

056. newBook.SetAttribute("publicationdate", "2001");

057. newBook.SetAttribute("ISBN", "123456789");

058.

059. //创建title元素

060. XmlElement newTitle = doc.createElement_x("title");

061. newTitle.InnerText = "The Case of the Missing Cookie";

062. //将title元素添加到book元素中

063. newBook.AppendChild(newTitle);

064.

065. XmlElement newAuthor = doc.createElement_x("author");

066. newBook.AppendChild(newAuthor);

067.

068. XmlElement newName = doc.createElement_x("name");

069. newName.InnerText = "C.Monster";

070. newAuthor.AppendChild(newName);

071.

072. XmlElement newPrice = doc.createElement_x("price");

073. newPrice.InnerText = "9.99";

074. newBook.AppendChild(newPrice);

075.

076. //将新建的book元素加入到XML文档中

077. doc.DocumentElement.AppendChild(newBook);

078.

079. //另存为

080. XmlTextWriter tr = new XmlTextWriter(@"..\..\booksEdit.xml", null);

081. tr.Formatting = Formatting.Indented;

082. doc.WriteContentTo(tr);

083. tr.Close();

084. Console.WriteLine("\nbooksEdit.xml Saved successful.\n");

085.

086. XmlNodeList nodes = doc.getElementsByTagName_r("title");

087. Console.WriteLine("Display title after Insert:");

088. foreach (XmlNode node in nodes)

089. {

090. Console.WriteLine(node.InnerText);

091. }

092. }

093.

094. //创建文档

095. public static void CreateDoc()

096. {

097. XmlDocument newDoc = new XmlDocument();

098.

099. //创建声明节点

100. XmlDeclaration newDec = newDoc.CreateXmlDeclaration("1.0", "utf-8", null);

101. newDoc.AppendChild(newDec);

102.

103. XmlElement newRoot = newDoc.createElement_x("bookstore");

104. newDoc.AppendChild(newRoot);

105.

106. XmlElement newBook = newDoc.createElement_x("book");

107. newBook.SetAttribute("genre", "MyStery");

108. newBook.SetAttribute("publicationdate", "2001");

109. newBook.SetAttribute("ISBN", "123456789");

110.

111. XmlElement newTitle = newDoc.createElement_x("title");

112. newTitle.InnerText = "The Case of the Missing Cookie";

113. newBook.AppendChild(newTitle);

114.

115. XmlElement newAuthor = newDoc.createElement_x("author");

116. newBook.AppendChild(newAuthor);

117.

118. XmlElement newName = newDoc.createElement_x("name");

119. newName.InnerText = "C.Monster";

120. newAuthor.AppendChild(newName);

121.

122. XmlElement newPrice = newDoc.createElement_x("price");

123. newPrice.InnerText = "9.99";

124. newBook.AppendChild(newPrice);

125.

126. newRoot.AppendChild(newBook);

127.

128. XmlTextWriter tr = new XmlTextWriter(@"..\..\booksCreate.xml", null);

129. tr.Formatting = Formatting.Indented;

130. newDoc.WriteContentTo(tr);

131. tr.Close();

132. Console.WriteLine("\nbooksCreate.xml Saved successful.\n");

133.

134. XmlNodeList nodes = newDoc.getElementsByTagName_r("title");

135. Console.WriteLine("Display title after Create:");

136. foreach (XmlNode node in nodes)

137. {

138. Console.WriteLine(node.InnerText);

139. }

140. }

141. }

142. }

books.xml:

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

02. <bookstore>

03. <book genre="autobiography" publicationdate="1991" ISBN="1-861003-11-0">

04. <title>The Autobiography of Benjamin Franklin</title>

05. <author>

06. <first-name>Benjamin</first-name>

07. <last-name>Franklin</last-name>

08. </author>

09. <price>8.99</price>

10. </book>

11. <book genre="novel" publicationdate="1967" ISBN="0-201-63361-2">

12. <title>The Confidence Man</title>

13. <author>

14. <first-name>Herman</first-name>

15. <last-name>Melville</last-name>

16. </author>

17. <price>11.99</price>

18. </book>

19. <book genre="philosophy" publicationdate="1991" ISBN="1-861001-57-6">

20. <title>The Gorgias</title>

21. <author>

22. <name>Plato</name>

23. </author>

24. <price>9.99</price>

25. </book>

26. </bookstore>

booksEdit.xml:修改后的XML文档

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

02. <bookstore>

03. <book genre="autobiography" publicationdate="1991" ISBN="1-861003-11-0">

04. <title>The Autobiography of Benjamin Franklin</title>

05. <author>

06. <first-name>Benjamin</first-name>

07. <last-name>Franklin</last-name>

08. </author>

09. <price>8.99</price>

10. </book>

11. <book genre="novel" publicationdate="1967" ISBN="0-201-63361-2">

12. <title>The Confidence Man</title>

13. <author>

14. <first-name>Herman</first-name>

15. <last-name>Melville</last-name>

16. </author>

17. <price>11.99</price>

18. </book>

19. <book genre="philosophy" publicationdate="1991" ISBN="1-861001-57-6">

20. <title>The Gorgias</title>

21. <author>

22. <name>Plato</name>

23. </author>

24. <price>9.99</price>

25. </book>

26. <book genre="MyStery" publicationdate="2001" ISBN="123456789">

27. <title>The Case of the Missing Cookie</title>

28. <author>

29. <name>C.Monster</name>

30. </author>

31. <price>9.99</price>

32. </book>

33. </bookstore>

booksCreate.xml:新建的XML文档

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

02. <bookstore>

03. <book genre="MyStery" publicationdate="2001" ISBN="123456789">

04. <title>The Case of the Missing Cookie</title>

05. <author>

06. <name>C.Monster</name>

07. </author>

08. <price>9.99</price>

09. </book>

10. </bookstore>