Loading and parsing XML files

Load and parse XML file 1.XML format

<?xml version= "1.0" encoding= "Utf-8"?> represents the XML file version, encoding used for internal text

<root> represents the root node

<CityName> Beijing </CityName> Beijing A junction, CityName is the node name, Beijing Junction point value

<item key= "1" value= "A" ></Item> key= "1" is a node attribute, key property name, "1" property value

Note: The XML structure is understood as a layered nested tree structure

<?XML version= "1.0" encoding= "Utf-8"?><Root>    <Systemconfig>      <CityName>Beijing</CityName>      <Citycode>201</Citycode>      <Parentcitycode>0</Parentcitycode>      <AreaCode>010</AreaCode>      <Agreementurl></Agreementurl>      <Intentionlevel>                               <ItemKey= "1"value= "A"></Item>        <ItemKey= "2"value= "B"></Item>        <ItemKey= "3"value= "C"></Item>      </Intentionlevel>      <Comechannel>                                   <ItemKey= "1"value= "Newspaper"></Item>        <ItemKey= "2"value= "Magazine"></Item>      </Comechannel>      <Buycarbudget>                               <ItemKey= "1"value= "40.5 million"></Item>        <ItemKey= "2"value= "50.6 million"></Item>      </Buycarbudget>     <Intentioncolor>         <ItemKey= "1"value= "Red"></Item>         <ItemKey= "2"value= "Yellow"></Item>     </Intentioncolor>    </Systemconfig></Root>

2.XML parsing 1. Configure the XML library (to use after configuration)

    // (1) Add header file search path     //       Header Search paths->/usr/include/libxml2    //(2) Add binary library     //   Link Library-  lixml2.dylib    //(3) source file Add compilation options     //        -fno-objc-arc    //(4) Add header file     //  # Import "GDataXMLNode.h"

2.GData use

 //1. Loading and parsing XML filesNSString *path = [[NSBundle mainbundle] Pathforresource:@"Xml.txt"Oftype:nil]; NSData*data =[[NSData alloc] initwithcontentsoffile:path]; //gdataxmldocument represents an XML Document Object//Initwithdata using NSData initialization is the parsingGdataxmldocument *doc = [[Gdataxmldocument alloc] initwithdata:data options:0Error:nil]; //2. Get instruction Syntax XPath//cityname Path:/root/systemconfig/citynameNsarray*array = [Doc Nodesforxpath:@"/root/systemconfig/cityname"Error:nil]; Gdataxmlelement*element =[Array firstobject]; NSLog (@"name =%@ value =%@", Element.name,element.stringvalue); //gets the properties of the specified nodeNsarray *items = [Doc Nodesforxpath:@"/root/systemconfig/comechannel/item"Error:nil]; Gdataxmlelement*item =[Items Firstobject]; //Property , the attribute is represented using gdataxmlelement     for(Gdataxmlelement *attrinchitem.attributes) {NSLog (@"name =%@ value =%@", Attr.name,attr.stringvalue); }        //4. Get all nodes of the specified name, regardless of location//XPath Syntax://ItemNsarray*allitem = [Doc Nodesforxpath:@"//item"Error:nil];  for(Gdataxmlelement *einchAllitem) {NSLog (@"name =%@", e.name); }        //5. Gets all properties of the specified name, regardless of location//XPath Syntax://@valueNsarray *allvalue = [Doc Nodesforxpath:@"//@value"Error:nil];  for(Gdataxmlelement *einchallvalue) {NSLog (@"value =%@", E.stringvalue); }        //6. Iterate through the XML file layer by row//Get root node//gdataxmlelement *root = doc.rootelement; //Get child nodes//Root.children//gets the number of child nodes//Root.childrencount//Gets the child node of the specified name//Root Elementsforname

3. More detailed XML parsing syntax XPath syntax

Link URL: http://www.w3school.com.cn/xpath/xpath_syntax.asp

Loading and parsing XML files