<response result="success" timestamp="1338890206" cityver="1.0">
<ttscity citycode="CHXX0094" url="http://i.apps.sina.cn/tqt/cit/CHXX0094.cit"/>
</response>
GDataXMLDocument *gData = [[GDataXMLDocument alloc] initWithData:data options:GDataXMLDocumentKind error:nil];
// 2. 获得根结点
GDataXMLElement *root = [gData rootElement];
// 3. 获得想要的结点
NSArray *lists = [root nodesForXPath:@"ttscity" error:nil];
GDataXMLElement *ele = lists.lastObject;
NSArray *array2 = ele.attributes;
GDataXMLNode *node = array2.firstObject;
NSString *cityNode = [node stringValue];