//1.加載和解析XML文件    NSString *path = [[NSBundle mainBundle] pathForResource:@"xml.txt" ofType:nil];    NSData *data = [[NSData alloc] initWithContentsOfFile:path];    // GDataXMLDocument 表示XML文檔對象    // initWithData 使用NSData初始化, 就是解析    GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:data options:0 error:nil];        //2.獲取指定結點 XPath    //CityName路徑: /root/systemConfig/CityName    NSArray *array = [doc nodesForXPath:@"/root/systemConfig/CityName" error:nil];    //CityName    GDataXMLElement *element = [array firstObject];    NSLog(@"name=%@ value=%@",element.name,element.stringValue);        //3.獲取指定結點的屬性    NSArray *items = [doc nodesForXPath:@"/root/systemConfig/ComeChannel/Item" error:nil];    GDataXMLElement *item = [items firstObject];    //獲取屬性, 屬性使用GDataXMLElement表示    for(GDataXMLElement *attr  in item.attributes)    {        NSLog(@"a-name=%@ avalue=%@",attr.name,attr.stringValue);    }            //4.獲取所有指定名字的結點(不管位置)    //XPath語法: //Item    NSArray *allItem = [doc nodesForXPath:@"http://Item" error:nil];    for (GDataXMLElement *e in allItem) {        NSLog(@"name = %@",e.name);    }        //5.獲取所有指定名字的屬性(不管哪個結點的)    //XPath語法: //@value    NSArray *allValue = [doc nodesForXPath:@"http://@value" error:nil];    for (GDataXMLElement *e in allValue) {        NSLog(@"value = %@",e.stringValue);    }        //6.逐層遍歷XML文件    //獲取根節點    GDataXMLElement *root = doc.rootElement;    //獲取子節點    //root.children    //獲取子節點個數    //root.childCount    //獲取指定名字的子節點    //root elementsForName:<#(NSString *)#>}