C # To operate XML files (read/write, modify, delete, and delete all contacts)

Common Operations:

XmlDocument xmlDoc = new XmlDocument (); <br/> xmlDoc. Load ("bookstore. xml"); <br/> // xmlDoc. LoadXml ("<! -- L version =/"1.0/" encoding =/"gb2312/--> <BOOKSTORE> </BOOKSTORE>"); <br/> XmlNode root = xmlDoc. selectSingleNode ("bookstore"); // find <BOOKSTORE> </BOOKSTORE> <br/> XmlElement xe1 = xmlDoc. createElement ("book"); // create a <BOOK> </BOOK> node <br/> xe1.SetAttribute ("genre", "Li zanhong "); // set genre attributes of the node <br/> xe1.SetAttribute ("ISBN", "2-3631-4 "); // set the ISBN attribute of the node </p> <p> XmlElement xesub1 = xmlDoc. createElement ("title"); <br/> xesub1.InnerText = "CS from entry to entry"; // set a text node <br/> xe1.AppendChild (xesub1 ); // Add it to the <BOOK> </BOOK> node <br/> XmlElement xesub2 = xmlDoc. createElement ("author"); <br/> xesub2.InnerText = ""; <br/> xe1.AppendChild (xesub2); </p> <p> XmlElement xesub3 = xmlDoc. createElement ("price"); <br/> xesub3.InnerText = "58.3"; <br/> xe1.AppendChild (xesub3); </p> <p> root. appendChild (xe1); // Add it to the <BOOKSTORE> </BOOKSTORE> node <br/> xmlDoc. save ("bookstore. xml "); <br/>

It is known that there is an XML file (bookstore. xml) as follows:
<? Xml version = "1.0" encoding = "gb2312"?>
<Bookstore>
<Book genre = "fantasy" ISBN = "2-3631-4">
<Title> Oberon's Legacy </title>
<Author> Corets, Eva </author>
<Price> 5.95 </price>
</Book>
</Bookstore>

1. Insert a <book> node to the <bookstore> node:
 

XmlDocument xmlDoc = new XmlDocument (); <br/> xmlDoc. Load ("bookstore. xml"); <br/> // xmlDoc. LoadXml ("<! -- L version =/"1.0/" encoding =/"gb2312/--> <BOOKSTORE> </BOOKSTORE>"); <br/> XmlNode root = xmlDoc. selectSingleNode ("bookstore"); // find <BOOKSTORE> </BOOKSTORE> <br/> XmlElement xe1 = xmlDoc. createElement ("book"); // create a <BOOK> </BOOK> node <br/> xe1.SetAttribute ("genre", "Li zanhong "); // set genre attributes of the node <br/> xe1.SetAttribute ("ISBN", "2-3631-4 "); // set the ISBN attribute of the node </p> <p> XmlElement xesub1 = xmlDoc. createElement ("title"); <br/> xesub1.InnerText = "CS from entry to entry"; // set a text node <br/> xe1.AppendChild (xesub1 ); // Add it to the <BOOK> </BOOK> node <br/> XmlElement xesub2 = xmlDoc. createElement ("author"); <br/> xesub2.InnerText = ""; <br/> xe1.AppendChild (xesub2); <br/> XmlElement xesub3 = xmlDoc. createElement ("price"); <br/> xesub3.InnerText = "58.3"; <br/> xe1.AppendChild (xesub3); </p> <p> root. appendChild (xe1); // Add it to the <BOOKSTORE> </BOOKSTORE> node <br/> xmlDoc. save ("bookstore. xml "); <br/>

// ================================================ ==========
Result:
<? Xml version = "1.0" encoding = "gb2312"?>
<Bookstore>
<Book genre = "fantasy" ISBN = "2-3631-4">
<Title> Oberon's Legacy </title>
<Author> Corets, Eva </author>
<Price> 5.95 </price>
</Book>
<Book genre = "Li zanhong" ISBN = "2-3631-4">
<Title> CS from entry to entry </title>
<Author> Hou Jie </author>
<Price> 58.3 </price>
</Book>
</Bookstore>

2. Modify the node: Change the genre value of the node whose genre attribute value is "Li zenhong" to "update Li zenhong ", modify the text of the child node <author> of the node to "Yasheng ".
 

1. XmlNodeList nodeList = xmlDoc. selectSingleNode ("bookstore "). childNodes; // obtain all the subnodes of the bookstore node <br/> foreach (XmlNode xn in nodeList) // traverse all sub-nodes <br/>{< br/> XmlElement xe = (XmlElement) xn; // convert the subnode type to the XmlElement type <br/> if (xe. getAttribute ("genre") = "") // If the genre attribute value is "" <br/>{< br/> xe. setAttribute ("genre", "update lizan red"); // modify the attribute to "update lizan red" </p> <p> XmlNodeList nls = xe. childNodes; // continue to obtain all the child nodes of the xe subnode <Br/> foreach (XmlNode xn1 in nls) // traverse <br/>{< br/> XmlElement xe2 = (XmlElement) xn1; // Conversion Type <br/> if (xe2.Name = "author") // if <br/>{< br/> xe2.InnerText = "Yasheng" is found "; // modify <br/> break; // find and exit <br/>}< br/> break; <br/>}</p> <p> xmlDoc. save ("bookstore. xml "); // save.

// ================================================ ================
The final result is:
<? Xml version = "1.0" encoding = "gb2312"?>
<Bookstore>
<Book genre = "fantasy" ISBN = "2-3631-4">
<Title> Oberon's Legacy </title>
<Author> corets, Eva </author>
<Price> 5.95 </price>
</Book>
<Book genre = "Update Li zanhong" ISBN = "2-3631-4">
<Title> Cs from entry to entry </title>
<Author> Yasheng </author>
<Price> 58.3 </price>
</Book>
</Bookstore>

3. Delete the genre attribute of the <book genre = "Fantasy" ISBN = "2-3631-4"> node, delete the <book genre = "Update lizan red" ISBN = "2-3631-4"> node.

Xmlnodelist xnl = xmldoc. selectsinglenode ("Bookstore "). childnodes; foreach (xmlnode Xn in xnl) {xmlelement Xe = (xmlelement) xn; If (Xe. getattribute ("genre") = "Fantasy") {Xe. removeattribute ("genre"); // Delete genre attribute} else if (Xe. getattribute ("genre") = "Update lizan red") {Xe. removeall (); // delete all content of the node} xmldoc. save ("Bookstore. XML ");

// ================================================ =====
The final result is:
<? XML version = "1.0" encoding = "gb2312"?>
<Bookstore>
<Book ISBN = "2-3631-4">
<Title> Oberon's legacy </title>
<Author> corets, Eva </author>
<Price> 5.95 </price>
</Book>
<Book>
</Book>
</Bookstore>

4. display all data.
 

1. XmlNode xn = xmlDoc. selectSingleNode ("bookstore"); </p> <p> XmlNodeList xnl = xn. childNodes; </p> <p> foreach (XmlNode xnf in xnl) <br/> {<br/> XmlElement xe = (XmlElement) xnf; <br/> Console. writeLine (xe. getAttribute ("genre"); // display the property value <br/> Console. writeLine (xe. getAttribute ("ISBN"); </p> <p> XmlNodeList xnf1 = xe. childNodes; <br/> foreach (XmlNode xn2 in xnf1) <br/>{< br/> Console. writeLine (xn2.InnerText); // displays the child node text <br/>}< br/>}

 

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