In C #, how does one modify, add, delete, and insert XML files?

In C #, how does one modify, add, delete, and insert XML files?

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 ();
Xmldoc. Load ("Bookstore. xml ");
Xmlnode root = xmldoc. selectsinglenode ("Bookstore"); // query <bookstore>
Xmlelement xe1 = xmldoc. createelement ("book"); // create a <book> node
Xe1.setattribute ("genre", "lizan red"); // you can specify the genre attribute of the node.
Xe1.setattribute ("ISBN", "2-3631-4"); // you can specify the ISBN attribute of the node.

Xmlelement xesub1 = xmldoc. createelement ("title ");
Xesub1.innertext = "Cs from entry to entry"; // set a text node
Xe1.appendchild (xesub1); // Add it to the <book> node
Xmlelement xesub2 = xmldoc. createelement ("author ");
Xesub2.innertext = "Hou Jie ";
Xe1.appendchild (xesub2 );
Xmlelement xesub3 = xmldoc. createelement ("price ");
Xesub3.innertext = "58.3 ";
Xe1.appendchild (xesub3 );

Root. appendchild (xe1); // Add it to the <bookstore> node
Xmldoc. Save ("Bookstore. xml ");

// ==========================
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 ".

Xmlnodelist nodelist = xmldoc. selectsinglenode ("Bookstore"). childnodes; // obtain all the subnodes of the bookstore Node
Foreach (xmlnode Xn in nodelist) // traverses all subnodes
{
Xmlelement Xe = (xmlelement) xn; // converts the subnode type to the xmlelement type
If (Xe. getattribute ("genre") = "") // If the genre attribute value is ""
{
Xe. setattribute ("genre", "Update lizan red"); // you can change this attribute to "Update lizan red"

Xmlnodelist NLS = Xe. childnodes; // continue to obtain all the child nodes of the Xe subnode
Foreach (xmlnode xn1 in NLS) // traverse
{
Xmlelement xe2 = (xmlelement) xn1; // Conversion Type
If (xe2.name = "author") // If you find
{
Xe2.innertext = "Yasheng"; // modify
Break; // find and exit.
}
}
Break;
}
}

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 attributes
}
Else if (Xe. getattribute ("genre") = "Update lizanhong ")
{
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.

Xmlnode xn = xmldoc. selectsinglenode ("Bookstore ");

Xmlnodelist xnl = xn. childnodes;

Foreach (xmlnode xnf in xnl)
{
Xmlelement Xe = (xmlelement) xnf;
Console. writeline (Xe. getattribute ("genre"); // display attribute values
Console. writeline (Xe. getattribute ("ISBN "));

Xmlnodelist xnf1 = Xe. childnodes;
Foreach (xmlnode xn2 in xnf1)
{
Console. writeline (xn2.innertext); // displays the child node text.
}
}

In addition:
Using system;
Using system. IO;
Using system. Web;
Using system. text;
Using system. xml;
Using system. collections;

 
Namespace shopweb. Class
{
/// <Summary>
/// Log summary.
/// </Summary>
Public class log
{
Private xmldocument xmllog = new xmldocument ();
Private httpcontext context = httpcontext. Current;
Private string xmlpath = "";
/// <Summary>
/// Constructor
/// </Summary>
/// <Param name = "xmlpath"> </param>
Public log (string xmlpath)
{

Xmlpath = xmlpath;
Xmllog. Load (context. server. mappath (xmlpath ));
}
/// <Summary>
/// Add a node that consists of subnodes
/// </Summary>
/// <Param name = "htchilds"> </param>
/// <Param name = "parentname"> </param>
/// <Returns> </returns>
Public bool addnodebychild (hashtable htchilds, string parentname)
{
Try
{

Xmlnode parent = xmllog. createelement (parentname );
Xmlnode child;
Idictionaryenumerator myenumerator = htchilds. getenumerator ();

While (myenumerator. movenext ())
{
Child = xmllog. createelement (myenumerator. Key. tostring ());
Child. innertext = myenumerator. value. tostring ();
Parent. appendchild (child );
Xmllog. documentelement. appendchild (parent );

}
Xmllog. Save (context. server. mappath (xmlpath ));
Return true;
}
Catch
{
Return false;

}

}
/// <Summary>
/// Add a node. The Node consists of attributes.
/// </Summary>
/// <Param name = "htattributes"> </param>
/// <Param name = "nodename"> </param>
/// <Returns> </returns>
Public bool addnodebyattribute (hashtable htattributes, string nodename)
{
Try
{
Xmlnode addnode = xmllog. createelement (nodename );
Idictionaryenumerator myenumerator = htattributes. getenumerator ();
Xmlattribute recognition;
While (myenumerator. movenext ())
{
Recognition = xmllog. createattribute (myenumerator. Key. tostring ());
Recognition. innertext = myenumerator. value. tostring ();
Addnode. Attributes. append (ASD );
Xmllog. documentelement. appendchild (addnode );

}
Xmllog. Save (context. server. mappath (xmlpath ));
Return true;
}
Catch
{
Return false;

}

}
/// <Summary>
/// Or specify the number of subnodes to be queried.
/// </Summary>
/// <Param name = "querypath"> </param>
/// <Returns> </returns>
Public int childcount (string querypath)
{
Try
{
Xmlnode resultnodes = xmllog. selectsinglenode (querypath );
Return resultnodes. childnodes. count;

}
Catch
{
Return-1;

}

}
/// <Summary>
/// Delete the node in the specified path
/// </Summary>
/// <Param name = "querypath"> </param>
/// <Returns> </returns>
Public bool deleltenode (string querypath)
{
Try
{
Xmlnodelist resultnodes = xmllog. selectnodes (querypath );
For (INT I = 0; I <resultnodes. Count; I ++)
{
Xmlnode parentnode = resultnodes [I]. parentnode;
Parentnode. removechild (resultnodes [I]);

}
Xmllog. Save (context. server. mappath (xmlpath ));
Return true;

}
Catch
{
Return false;
}

}
/// <Summary>
/// Query a node
/// </Summary>
/// <Param name = "querypath"> </param>
/// <Returns> </returns>
Public xmlnodelist querynode (string querypath)
{
Try
{
Xmlnodelist resultnodes = xmllog. selectnodes (querypath );
Return resultnodes;
}
Catch
{
Return NULL;
}

}
}
}

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From: http://blog.csdn.net/xiaowu703/archive/2004/09/27/118833.aspx