C # XML additions and deletions check and change

C # XML XmlDocument

To add a namespace:

Using System.Xml;

To define a common object:

XmlDocument xmldoc; XmlNode XmlNode; XmlElement Xmlelem;

1, create an XML file to the server directory with the same name:

Method One:

xmldoc = new XmlDocument ();//Add XML to the declaration paragraph, <?xml version= "1.0" encoding= "gb2312"? >xmldeclaration xmldecl;xmldecl = XmlDoc. Createxmldeclaration ("1.0", "gb2312", null); xmldoc. AppendChild (XMLDECL);//Add a root element Xmlelem = xmldoc. CreateElement ("", "Employees", ""); xmldoc. AppendChild (Xmlelem);//Add another element for (int i=1;i<3;i++) {XmlNode root=xmldoc. selectSingleNode ("Employees");//Find <Employees> XmlElement xe1=xmldoc. CreateElement ("node");//Create a <Node> node xe1. SetAttribute ("Genre", "doucube");//Set the node genre property xe1. SetAttribute ("ISBN", "2-3631-4");//Set the Node ISBN property XmlElement Xesub1=xmldoc.     CreateElement ("title"); Xesub1. Innertext= "CS from beginner to proficient";//Set Text node Xe1. AppendChild (XESUB1);//Add to the <Node> node XmlElement xesub2=xmldoc.     CreateElement ("author"); Xesub2.     Innertext= "Waiting for the Czech Republic"; Xe1.     AppendChild (XESUB2); XmlElement Xesub3=xmldoc.     CreateElement ("Price"); Xesub3.     innertext= "58.3"; Xe1.     AppendChild (XESUB3); Root. AppendChild (XE1);//Add to <Employees> node}//Save the created XML document Xmldoc.save (Server.MapPath ("Data.xml"));  

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Result: A file named Data.xml was generated under the same name, with the following

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" >< Title>cs from getting started to mastering </title><author> waiting </author><price>58.3</price></Node>< Node genre= "Doucube" isbn= "2-3631-4" ><title>cs from Getting started to mastering </title><author> waiting </author>< Price>58.3</price></node></employees>

Method Two:

XmlTextWriter xmlwriter;string strFileName = Server.MapPath ("Data1.xml"); xmlWriter = new XmlTextWriter (StrFilename, Encoding.default);//Create an XML document xmlwriter.formatting = Formatting.indented;xmlwriter.writestartdocument (); Xmlwriter.writestartelement ("Employees"); Xmlwriter.writestartelement ("Node"); Xmlwriter.writeattributestring (" Genre "," Doucube "); Xmlwriter.writeattributestring (" ISBN "," 2-3631-4 "); Xmlwriter.writestartelement (" title "); Xmlwriter.writestring ("CS from beginner to Proficient"); Xmlwriter.writeendelement (); Xmlwriter.writestartelement ("author"); Xmlwriter.writestring ("Waiting"); Xmlwriter.writeendelement (); Xmlwriter.writestartelement ("Price"); Xmlwriter.writestring ("58.3"); Xmlwriter.writeendelement (); Xmlwriter.writeendelement (); Xmlwriter.close ();

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Results:

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" >< Title>cs from getting started to mastering </title><author> waiting </author><price>58.3</price></Node>< /employees>

2, add a node:

XmlDocument xmldoc=new XmlDocument (); Xmldoc.load (Server.MapPath ("Data.xml")); XmlNode Root=xmldoc.selectsinglenode ("Employees");//Find <Employees> XmlElement xe1=xmldoc.createelement ("Node ");//Create a <Node> node xe1. SetAttribute ("Genre", "Zhang San");//Set the node genre property xe1. SetAttribute ("ISBN", "1-1111-1");//Set the Node ISBN property XmlElement xesub1=xmldoc.createelement ("title"); Xesub1. Innertext= "C # Getting Started help";//Set Text node Xe1. AppendChild (XESUB1);//Add to <Node> node XmlElement xesub2=xmldoc.createelement ("author"); Xesub2. innertext= "Master"; Xe1. AppendChild (XESUB2); XmlElement xesub3=xmldoc.createelement ("price"); Xesub3. innertext= "158.3"; Xe1. AppendChild (XESUB3); Root. AppendChild (XE1);//Add to the <Employees> node Xmldoc.save (Server.MapPath ("Data.xml"));

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Result: A node is added to the original XML content as follows,

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" >< Title>cs from getting started to mastering </title><author> waiting </author><price>58.3</price></Node>< Node genre= "Doucube" isbn= "2-3631-4" ><title>cs from Getting started to mastering </title><author> waiting </author>< Price>58.3</price></node><node genre= "Zhang San" isbn= "1-1111-1" ><title>c# Getting Started help </title> <author> Master </author><price>158.3</price></Node></Employees>

3, modify the value of the node (attributes and sub-nodes):

XmlDocument xmldoc=new XmlDocument (); Xmldoc.load (Server.MapPath ("Data.xml")); XmlNodeList Nodelist=xmldoc.selectsinglenode ("Employees"). childnodes;//get all child nodes of Employees node foreach (XmlNode xn in nodeList)//traverse all child nodes {     XmlElement xe= (XmlElement) xn;// Converts a child node type to a XmlElement type     if (XE). GetAttribute ("genre") = = "Zhang San")//if the genre attribute value is "Zhang San"     {         XE. SetAttribute ("Genre", "Update Zhang San");//Modify this property to "update Zhang San"         XmlNodeList nls=xe. childnodes;//continue to acquire all child nodes of the XE subnodes         foreach (XmlNode xn1 in NLS)//traversal         {             XmlElement xe2= (XmlElement) xn1;//conversion type             if (xe2. name== "Author")//If you find             {                 xe2. innertext= "Ya sheng";//Modify            }}}     Xmldoc.save (Server.MapPath ("Data.xml"));//save.

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Result: The original information of all the nodes have been modified, the content of the XML is as follows,

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" >< Title>cs from getting started to mastering </title><author> waiting </author><price>58.3</price></Node>< Node genre= "Doucube" isbn= "2-3631-4" ><title>cs from Getting started to mastering </title><author> waiting </author>< Price>58.3</price></node><node genre= "Update Zhang San" isbn= "1-1111-1" ><title>c# Getting Started help </ Title><author> </author><price>158.3</price></Node></Employees>

4, modify the node (add the node's attributes and add the node's self-node):

XmlDocument xmldoc=new XmlDocument (); Xmldoc.load (Server.MapPath ("Data.xml")); XmlNodeList Nodelist=xmldoc.selectsinglenode ("Employees"). childnodes;//gets all child nodes of the Employees node foreach (XmlNode xn in nodeList) {     XmlElement xe= (XmlElement) xn;     Xe. SetAttribute ("Test", "111111");    XmlElement xesub=xmldoc.createelement ("flag");     Xesub. innertext= "1";     Xe. AppendChild (xesub); } xmldoc.save (Server.MapPath ("Data.xml"));

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Result: The attributes of each node are added with one, and the sub-nodes are also added, the contents are as follows,

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" test= "111111 "><title>cs from beginner to proficient </title><author> </author><price>58.3</price><flag >1</flag></node><node genre= "Doucube" isbn= "2-3631-4" test= "111111" ><title>cs from getting started to mastering </title><author> </author><price>58.3</price><flag>1</flag></ Node><node genre= "Update Zhang San" isbn= "1-1111-1" test= "111111" ><title>c# Getting Started help </title><author > Ya sheng </author><price>158.3</price><flag>1</flag></Node></Employees>

5, delete one of the properties in the node:

XmlDocument xmldoc=new XmlDocument (); Xmldoc.load (Server.MapPath ("Data.xml")); XmlNodeList Xnl=xmldoc.selectsinglenode ("Employees"). ChildNodes; foreach (XmlNode xn in xnl) {     XmlElement xe= (XmlElement) xn;     Xe. RemoveAttribute ("genre");//Delete genre property     XmlNodeList Nls=xe. childnodes;//continue to acquire all child nodes of the XE subnodes     foreach (XmlNode xn1 in NLS)//traversal     {         XmlElement xe2= (XmlElement) xn1;//conversion type         if (xe2. name== "flag")//If you find         {             XE. RemoveChild (XE2);//Delete        }     

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Result: Delete A property of the endpoint and a sub-node of the node, as follows,

<?xml version= "1.0" encoding= "gb2312"? ><employees><node isbn= "2-3631-4" test= "111111" ><title >cs from beginner to proficient </title><author> </author><price>58.3</price></node><node Isbn= "2-3631-4" test= "111111" ><title>cs from Getting started to mastering </title><author> waiting </author><price >58.3</price></node><node isbn= "1-1111-1" test= "111111" ><title>c# Getting Started help </title> <author> ya sheng </author><price>158.3</price></Node></Employees>

6. Delete the node:

XmlDocument xmldoc=new XmlDocument (); Xmldoc.load (Server.MapPath ("Data.xml")); XmlNode Root=xmldoc.selectsinglenode ("Employees"); XmlNodeList Xnl=xmldoc.selectsinglenode ("Employees"). ChildNodes; for (int i=0;i<xnl. count;i++) {    XmlElement xe= (XmlElement) xnl. Item (i);     if (XE. GetAttribute ("genre") = = "Zhang San")     {         root. RemoveChild (XE);        if (I<XNL. Count) i=i-1;    

//////////////////////////////////////////////////////////////////////////////////////]
Result: Delete all the nodes that match the condition, the original content:

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" >< Title>cs from getting started to mastering </title><author> waiting </author><price>58.3</price></Node>< Node genre= "Doucube" isbn= "2-3631-4" ><title>cs from Getting started to mastering </title><author> waiting </author>< Price>58.3</price></node><node genre= "Zhang San" isbn= "1-1111-1" ><title>c# Getting Started help </title> <author> Master </author><price>158.3</price></node><node genre= "Zhang San" isbn= "1-1111-1" ><title>c# Getting Started help </title><author> expert </author><price>158.3</price></node ></Employees>

Content after deletion:

<?xml version= "1.0" encoding= "gb2312"? ><employees><node genre= "Doucube" isbn= "2-3631-4" >< Title>cs from getting started to mastering </title><author> waiting </author><price>58.3</price></Node>< Node genre= "Doucube" isbn= "2-3631-4" ><title>cs from Getting started to mastering </title><author> waiting </author>< Price>58.3</price></node></employees>

7, read the XML as a text file

System.IO.StreamReader myFile = new System.IO.StreamReader (Server.MapPath ("Data.xml"), System.Text.Encoding.Default );//Note System.Text.Encoding.Defaultstring myString = Myfile.readtoend ();//mystring is a read-out string myfile.close ();

C # XML additions and deletions check and change