转载自：
点击打开链接@GDataXMLNode是Google提供的用于XML数据处理的类集。该类集对libxml2-DOM处理方式进行了封装，能对较小或中等的XML文档进行读写操作且支持XPath语法。
1.
http://code.google.com/p/gdata-objectivec-client/source/browse/trunk/Source/XMLSupport/,获得GDataXMLNode.h和GDataXMLNode.m文件，进行如下操作将文件导入到Xcode的工程中：
2.将GDataXMLNode.h/m文件添加到工程中；
3.向工程中增加“libxml2.dylib”库；
4.在工程的“Build Settings”页中找到“Header Search Path”项，添加“/usr/include/libxml2”到其路径
5.搜索框中搜索Other linker flags，同样的方式添加-lxml2
@代码示例:
首先在工程中新建一个xml文件，作为我们要解析的对象，新建方法是在工程中新建一个Empty的文件，命名为Student.txt(可以命名为.xml,这个随意)，然后添加内容：
[html]
view plaincopy<?xml version="1.0" encoding="UTF-8"?>
<Students class="17班" school="中国">
<student>
<number>1</number>
<name>胡明涛</name>
<sex>男</sex>
<phone>123558</phone>
</student>
<student>
<number>2</number>
<name>成风采</name>
<sex>男</sex>
<phone>122323</phone>
</student>
<student>
<number>3</number>
<name>陈咬金</name>
<sex>男</sex>
<phone>21313558</phone>
</student>
<student sign="非应届生">
<number>4</number>
<name>天天下</name>
<sex>男</sex>
<phone>56453558</phone>
</student>
</Students>
[objc]
view plaincopy#pragma mark - GDataXMLNode
- (void)onClickGDataXMLButton{
// 获取工程目录的xml文件
NSData * xmlData = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"Student" ofType:@"txt"]];
// 从文档中读出完整的XML数据,在内存中形成完整的树形结构
NSError * error = nil;
GDataXMLDocument * documents = [[GDataXMLDocument alloc]initWithData:xmlData options:0 error:&error];
// 取得根节点(element元素)---Students
GDataXMLElement * rootEL = [documents rootElement];
// 获取根节点下的节点,返回的数组---student
NSArray * studentsArray = [rootEL elementsForName:@"student"];
for (int i = 0; i < [studentsArray count]; i++) {
// 获取单个节点对象
GDataXMLElement * student = [studentsArray objectAtIndex:i];
// 获取student节点下name,number,sex,phone节点的值
GDataXMLElement * nameElement = [[student elementsForName:@"name"] lastObject];
GDataXMLElement * sexElement = [[student elementsForName:@"sex"]lastObject];
GDataXMLElement * numberElement = [[student elementsForName:@"number"]lastObject];
GDataXMLElement * phoneElement = [[student elementsForName:@"phone"]lastObject];
NSString * name = [nameElement stringValue];
NSString * number = [numberElement stringValue];
NSString * sex = [sexElement stringValue];
NSString * phone = [phoneElement stringValue];
// 读标签里面的属性(attributeForName)
NSString * sign = [[student attributeForName:@"sign"]stringValue];
if (sign) {
NSLog(@"----------%@",sign);
}
NSLog(@"%@,%@,%@,%@",number,name,sex,phone);
}
#pragma mark 通过路径,取得指定的节点值,所有节点中同一标签的值
// 一个是相对路径,一个是绝对路径-----------(nodesForXPath)
//NSArray * nameArray = [rootEL nodesForXPath:@"//name" error:nil];
NSArray * nameArray = [rootEL nodesForXPath:@"student/name" error:nil];
for (int i = 0; i < [nameArray count]; i++) {
NSString * name = [[nameArray objectAtIndex:i] stringValue];
NSLog(@"---%@",name);
}
}
[html]
view plaincopy<?xml version="1.0"?>
<xml_api_reply version="1">
<cities>
<city>
<name data="保定"/>
<latitude_e6> 38849998</latitude_e6>
<longitude_e6> 115569999</longitude_e6>
</city>
<city default="true" >
<name data="北京"/>
<latitude_e6> 39930000</latitude_e6>
<longitude_e6> 116279998</longitude_e6>
</city>
<city>
<name data="沈阳"/>
<latitude_e6> 41770000</latitude_e6>
<longitude_e6> 123430000</longitude_e6>
</city>
<city>
<name data="成都"/>
<latitude_e6> 30670000</latitude_e6>
<longitude_e6> 104019996</longitude_e6>
</city>
<city>
<name data="大连"/>
<latitude_e6> 38900001</latitude_e6>
<longitude_e6> 121629997</longitude_e6>
</city>
<city>
<name data="福州"/>
<latitude_e6> 26079999</latitude_e6>
<longitude_e6> 119279998</longitude_e6>
</city>
<city>
<name data="阜阳"/>
<latitude_e6> 32930000</latitude_e6>
<longitude_e6> 115830001</longitude_e6>
</city>
<city>
<name data="赣州"/>
<latitude_e6> 25850000</latitude_e6>
<longitude_e6> 114949997</longitude_e6>
</city>
<city>
<name data="广州"/>
<latitude_e6> 23129999</latitude_e6>
<longitude_e6> 113319999</longitude_e6>
</city>
<city>
<name data="贵阳"/>
<latitude_e6> 26579999</latitude_e6>
<longitude_e6> 106720001</longitude_e6>
</city>
<city>
<name data="哈尔滨"/>
<latitude_e6> 45750000</latitude_e6>
<longitude_e6> 126769996</longitude_e6>
</city>
<city>
<name data="海口"/>
<latitude_e6> 20030000</latitude_e6>
<longitude_e6> 110349998</longitude_e6>
</city>
<city>
<name data="邯郸"/>
<latitude_e6> 38029998</latitude_e6>
<longitude_e6> 114419998</longitude_e6>
</city>
<city>
<name data="杭州"/>
<latitude_e6> 30229999</latitude_e6>
<longitude_e6> 120169998</longitude_e6>
</city>
<city>
<name data="合肥"/>
<latitude_e6> 31870000</latitude_e6>
<longitude_e6> 117230003</longitude_e6>
</city>
<city>
<name data="菏泽"/>
<latitude_e6> 36119998</latitude_e6>
<longitude_e6> 114370002</longitude_e6>
</city>
<city>
<name data="衡阳"/>
<latitude_e6> 36119998</latitude_e6>
<longitude_e6> 114370002</longitude_e6>
</city>
</cities>
</xml_api_reply>
[objc]
view plaincopy#pragma mark - 解析citys
- (void)parseCitys{
NSData * xmlCitysData = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"citys" ofType:@"xml"]];
// 从文档中读取完成的XML文档,在内存中形成完整的树形结构
NSError * error = nil;
GDataXMLDocument * documents = [[GDataXMLDocument alloc]initWithData:xmlCitysData options:0 error:&error];
// 取得根节点
GDataXMLElement * rootNode = [documents rootElement];
#pragma mark 获取根节点xml_api_reply的数组,包含的是cities
NSArray * citiesArray = [rootNode elementsForName:@"cities"];
for (int i = 0; i < [citiesArray count]; i++) {
// 取得单个cities节点
GDataXMLElement * cities = [citiesArray objectAtIndex:i];
#pragma mark 获取节点cities的数组,包含的是city
NSArray * cityArray = [cities elementsForName:@"city"];
for (int j = 0; j < [cityArray count]; j++) {
// 取得单个city节点
GDataXMLElement * city = [cityArray objectAtIndex:j];
#pragma mark city节点下面是3个并行的节点,都是1个,直接通过lastObject来取得想要的值
NSString * name = [[[[city elementsForName:@"name"]lastObject] attributeForName:@"data"] stringValue];
NSLog(@"name = %@",name);
NSString * latitude_e6 = [[[city elementsForName:@"latitude_e6"]lastObject] stringValue];
NSLog(@"latitude_e6 = %@",latitude_e6);
NSString * longitude_e6 = [[[city elementsForName:@"longitude_e6"]lastObject] stringValue];
NSLog(@"longitude_e6 = %@",longitude_e6);
}
}
}
