XmlDocument two create XML application instances

This is mainly about XmlDocument creating, deleting, editing, and inserting XML operations into nodes.

XmlDocument xmldoc = new XmlDocument ();
XmlNode XmlNode;
XmlElement Xmlelem;
XmlElement xmlelem2;
XmlText xmltext;

Declarative paragraphs that add XML
XmlNode = Xmldoc.createnode (Xmlnodetype.xmldeclaration, "", "");
Xmldoc.appendchild (XmlNode);
Add a root element
Xmlelem = Xmldoc.createelement ("", "Root", "");
XmlText = Xmldoc.createtextnode ("root text");
Xmlelem.appendchild (xmltext);
Xmldoc.appendchild (Xmlelem);
Add a different element
XMLELEM2 = Xmldoc.createelement ("sampleelement");
XMLELEM2 = Xmldoc.createelement ("", "Sampleelement", "");
XmlText = Xmldoc.createtextnode ("The text of the sample element");
Xmlelem2.appendchild (xmltext);
Xmldoc.childnodes.item (1). appendchild (XMLELEM2);
Save the created XML document
Try
{
Xmldoc.save ("G:/yunli/srcloud.web/uploads/filehistory/data.xml");
}
catch (Exception e)
{
Display error messages
Console.WriteLine (E.message);
}
Console.ReadLine ();
}

The above is simply created, the following example, XmlDocument create XML document and add Delete update node

using System;
Using System.Collections.Generic;
Using System.ComponentModel;
Using System.Data;
Using System.Drawing;
Using System.Text;
Using System.Windows.Forms;
Using System.Xml;
Namespace Xmldomdemo
{
public partial class Form1:form
{
Public Form1 ()
{
InitializeComponent ();
}

        private void Btnload_click (object sender, EventArgs e)
 & nbsp;      {
            XmlDocument xmldoc = new XmlDocument ();
            xmldoc.load ("books.xml");
            MessageBox.Show (xmldoc.innerxml);
       }
       //Create document
        private void Btncreate_click (object sender, EventArgs e)
        {
             XmlDocument xmldoc = new XmlDocument ();

Create a definition declaration for XML
XmlDeclaration Dec = xmldoc.createxmldeclaration ("1.0", "gb2312", null);
Xmldoc.appendchild (DEC);

To create a root node
XmlElement root = Xmldoc.createelement ("books");
Xmldoc.appendchild (root);

XmlNode book = xmldoc.createelement ("book");

XmlElement title = xmldoc.createelement ("title");
Title.innertext = "SQL Server";
Book.appendchild (title);

XmlElement ISBN = xmldoc.createelement ("ISBN");
Isbn.innertext = "444444";
Book.appendchild (ISBN);

XmlElement author = xmldoc.createelement ("author");
Author.innertext = "Jia";
Book.appendchild (author);

XmlElement price = Xmldoc.createelement ("price");
Price.innertext = "120";
Price.setattribute ("unit", "___fckpd___0quot;");

Book.appendchild (price);
Root.appendchild (book);

Xmldoc.save ("books.xml");
}

private void Btninsert_click (object sender, EventArgs e)
{
XmlDocument xmldoc = new XmlDocument ();
Xmldoc.load ("books.xml");

XmlNode root = Xmldoc.selectsinglenode ("books");

XmlElement book = xmldoc.createelement ("book");

XmlElement title = xmldoc.createelement ("title");
Title.innertext = "xml";
Book.appendchild (title);

XmlElement ISBN = xmldoc.createelement ("ISBN");
Isbn.innertext = "333333";
Book.appendchild (ISBN);

XmlElement author = xmldoc.createelement ("author");
Author.innertext = "Snow";
Book.appendchild (author);

XmlElement price = Xmldoc.createelement ("price");
Price.innertext = "120";
Price.setattribute ("unit", "___fckpd___0quot;");

Book.appendchild (price);

Root.appendchild (book);

Xmldoc.save ("books.xml");
MessageBox.Show ("Data has been written!") ");
}

private void Btnupdate_click (object sender, EventArgs e)
{
XmlDocument xmldoc = new XmlDocument ();
Xmldoc.load ("books.xml");

           //"//book[@unit =" $ "]"
            //Get all child nodes of the books node
             XmlNodeList nodelist = Xmldoc.selectsinglenode ("Books//book"). ChildNodes;

           //Traverse all child nodes
             foreach (XmlNode xn in nodelist)
             {
                //Convert child node type to XmlElement type
                 XmlElement XE = (XmlElement) xn;
                if (xe.name = = " Author ")
                {
                     Xe.innertext = "Amandag";
               }

if (Xe.getattribute ("unit") = = "___fckpd___0quot;)
{
Xe.setattribute ("unit", "￥");
}
Break
}

XmlNodeList nodelist = xmldoc.selectnodes ("Books//book");
foreach (XmlNode xn in nodelist)
//{
foreach (XmlNode x in Xn.childnodes)
//    {
To convert a child node type to a XmlElement type
XmlElement XE = (XmlElement) x;
if (Xe.name = = "Author")
//        {
Xe.innertext = "Amandag";
//        }

if (Xe.getattribute ("unit") = = "___fckpd___0quot;)
//        {
Xe.setattribute ("unit", "￥");
//        }
break;
//    }
//}
Xmldoc.save ("books.xml");
}

private void Btndelete_click (object sender, EventArgs e)
{
XmlDocument xmldoc = new XmlDocument ();
Xmldoc.load ("books.xml");

XmlNodeList nodelist = Xmldoc.selectsinglenode ("Books//book"). ChildNodes;

           //Traverse all child nodes
             foreach (XmlNode xn in nodelist)
             {
                //Convert child node type to XmlElement type
                 XmlElement XE = (XmlElement) xn;
                if (xe.name = = " Author ")
                {
                     Xe.removeall ();
               }

                if ( Xe.getattribute ("unit") = = "￥")
                 {
                     xe.removeattribute ("unit");
               }
           }
            xmldoc.save ("books.xml");
       }
   }
}