C # xml Operation Summary 2: read, insert, modify, and delete

C #: XML Operation Summary 2: read, insert, modify, and delete

1. Read the value of an attribute in the node.

/// <Summary> /// read the value of an attribute in a node. If attribute is empty, the innertext of the entire node is returned, otherwise, return the value of the specific attribute /// </Summary> /// <Param name = "path"> XML file path </param> /// <Param name = "Node "> node </param> /// <Param name =" attribute "> attributes of a node </param> /// <returns> If attribute is empty, the innertext of the entire node is returned; otherwise, the value of the specific attribute is returned </returns> // use instance: xmlhelper. read (path, "personf/person [@ name = 'person2']", ""); // xmlhelper. read (path, "personf/person [@ name = 'person2']", "name"); Public Static string read (string path, string node, string attribute) {string value = ""; try {xmldocument Doc = new xmldocument (); Doc. load (PATH); xmlnode xn = Doc. selectsinglenode (node); value = (attribute. equals ("")? XN. innertext: Xn. attributes [attribute]. Value);} catch (exception e) {console. writeline (E. Message) ;}return value ;}

2. Add node elements and attributes to the node.

/// <Summary> /// Add a node element to the node, properties /// </Summary> /// <Param name = "path"> path </param> /// <Param name = "Node"> node to be operated </param> // <Param name = "element"> the node element to be added, it can be empty. Insert a new element if it is not empty. Otherwise, insert the attribute of the element </param> // <Param name = "attribute"> to add the node attribute. It can be empty or empty. Insert the element value if it is not null, otherwise, insert the element value </param> /// <Param name = "value"> value of the node to be added </param> /// use the instance xmlhelper. insert (path, "personf/person [@ name = 'person2']", "num", "ID", "88"); // xmlhelper. insert (path, "personf/person [@ name = 'person2']", "num", "", "88"); // xmlhelper. insert (path, "personf/person [@ name = 'person2']", "", "ID", "88"); public static void insert (string path, string node, string element, string attribute, string Value) {try {xmldocument Doc = new xmldocument (); Doc. load (PATH); xmlnode xn = Doc. selectsinglenode (node); // If the element is used, this attribute if (string. isnullorempty (element) {// If attribute is not empty, add this attribute if (! String. isnullorempty (attribute) {xmlelement Xe = (xmlelement) xn; // <person name = "person2" id = "88"> xmlhelper. insert (path, "personf/person [@ name = 'person2']", "num", "ID", "88"); Xe. setattribute (attribute, value) ;}} else // If the element is not empty, add the node {xmlelement Xe = Doc under preson. createelement (element); If (string. isnullorempty (attribute) // <person> <num> 88 </num> </person> xmlhelper. insert (path, "personf/person [@ name = 'person2']", "num", "", "88"); Xe. innertext = value; else // <person> <num id = "88"/> </person> xmlhelper. insert (path, "personf/person [@ name = 'person2']", "", "ID", "88"); Xe. setattribute (attribute, value); XN. appendchild (xe);} Doc. save (PATH);} catch (exception e) {console. writeline (E. message );}}

3. Modify node values

/// <Summary> /// modify the node value /// </Summary> /// <Param name = "path"> path </param> /// <Param name = "Node"> the node to be modified </param> // <Param name = "attribute"> attribute name, if it is not empty, modify the node attribute value. Otherwise, modify the node value </param> /// <Param name = "value"> attribute value </param> // xmlhelper instance. update (path, "personf/person [@ name = 'person3']/ID", "", "888"); // xmlhelper. update (path, "personf/person [@ name = 'person3']/ID", "num", "999"); public static void Update (string path, string node, string attribute, string value) {try {xmldocument Doc = new xmldocument (); Doc. load (PATH); xmlnode xn = Doc. selectsinglenode (node); xmlelement Xe = (xmlelement) xn; If (string. isnullorempty (attribute) Xe. innertext = value; // The original <ID> 2 </ID> is changed: <ID> 888 </ID> xmlhelper. update (path, "personf/person [@ name = 'person3']/ID", "", "888"); else Xe. setattribute (attribute, value); // The original <ID num = "3"> 888 </ID> variable <ID num = "999"> 888 </ID> xmlhelper. update (path, "personf/person [@ name = 'person3']/ID", "num", "999"); Doc. save (PATH);} catch (exception e) {console. writeline (E. message );}}

　　

4. delete data

/// <Summary> /// delete data /// </Summary> /// <Param name = "path"> path </param> /// <Param name = "Node"> the node to be deleted </param> // <Param name = "attribute"> attribute, if it is null, the entire node is deleted. If it is not null, the attributes of the node are deleted </param> // instance: xmlhelper. delete (path, "personf/person [@ name = 'person3']/ID", ""); // xmlhelper. delete (path, "personf/person [@ name = 'person3']/ID", "num"); public static void Delete (string path, string node, string attribute) {try {xmldocument Doc = new xmldocument (); Doc. load (PATH); xmlnode xn = Doc. selectsinglenode (node); xmlelement Xe = (xmlelement) xn; If (string. isnullorempty (attribute) xn. parentnode. removechild (Xn); // The entire node of <ID num = "999"> 888 </ID> will be removed from xmlhelper. delete (path, "personf/person [@ name = 'person3']/ID", ""); else Xe. removeattribute (attribute); // <ID num = "999"> 888 </ID> to <ID> 888 </ID> xmlhelper. delete (path, "personf/person [@ name = 'person3']/ID", "num"); Doc. save (PATH);} catch (exception e) {console. writeline (E. message );}}

　　

5. Call Method

      public static void XMLMTest()        {            string path = "http://www.cnblogs.com/../Person.xml";            XMLHelper.Read(path, "PersonF/person[@Name='Person2']", "Name");            XMLHelper.Insert(path, "PersonF/person[@Name='Person2']", "Num", "ID", "88");            XMLHelper.Insert(path, "PersonF/person[@Name='Person2']", "Num", "", "88");            XMLHelper.Insert(path, "PersonF/person[@Name='Person2']", "", "ID", "88");            XMLHelper.Update(path, "PersonF/person[@Name='Person3']", "Num", "888");            XMLHelper.Update(path, "PersonF/person[@Name='Person3']/ID", "Num", "999");            XMLHelper.Update(path, "PersonF/person[@Name='Person3']/ID", "", "888");            XMLHelper.Delete(path, "PersonF/person[@Name='Person3']/ID", "Num");            XMLHelper.Delete(path, "PersonF/person[@Name='Person3']/ID", "");        }

　　

6. xml files

<?xml version="1.0" encoding="utf-8"?><PersonF xmlns="" Name="work hard work smart!">  <person Name="Person1">    <ID>1</ID>    <Name>XiaoA</Name>    <Age>59</Age>  </person>  <person Name="Person2" ID="88">    <ID>2</ID>    <Name>XiaoB</Name>    <Age>29</Age>    <Num ID="88" />    <Num>88</Num>  </person>  <person Name="Person3">    <ID Num="999">888</ID>    <Name>XiaoC</Name>    <Age>103</Age>  </person>  <person Name="Person4">    <ID>4</ID>    <Name>XiaoD</Name>    <Age>59</Age>  </person>  <person Name="Person5">    <Name>work hard work smart!</Name>    <ID>32</ID>  </person>  <person Name="Person5">    <Name>work hard work smart!</Name>    <ID>32</ID>  </person></PersonF>

　

The following is a summary of C #'s specific XML operations.

C # xml Operation Summary 2: read, insert, modify, and delete

How to read and write XML documents in. net

C # operating XML selectnodes, selectsinglenode always returns NULL and XPath Introduction

C # Use selectsinglenode to parse XML files with multiple namespaces