QML处理xml使用的是XmlListModel + XmlRole，基本的操作可以参考官方文档，说的很清楚。

使用query查询目标节点时，如果包含 namespace，如“a:book”，则会查询到null。

如果声明的是默认命名空间，如

<xml_api_reply xmlns="http://duino.com/" version="1">

需要如下处理：

XmlListModel {
    source: "http://mysite.com/Feed.xml"
    query: "/Feed/entry"
    <strong><span style="color:#ff0000;">namespaceDeclarations: "declare default element namespace 'http://duino.com/';"</span></strong>

    XmlRole { name: "title"; query: "title/string()" }
}

<RSSxmlns:yweather="http://xml.weather.yahoo.com/ns/RSS/1.0"version="2.0">
......

<yweather:forecastday="Tue"date="24 Feb 2015"low="11"high="17"text="Partly Cloudy"code="30"/>

......

需要如下处理：

<span style="white-space:pre">	</span>XmlListModel { 
	<span style="white-space:pre">	</span>id: weatherModelForecast
		source: "http://weather.yahooapis.com/forecastRSS?w=2133704&u=c"
		query: "/RSS/channel/item/yweather:forecast"
		<strong><span style="color:#ff0000;">namespaceDeclarations: "declare namespace yweather='http://xml.weather.yahoo.com/ns/RSS/1.0';"</span></strong>

		XmlRole { name: "day"; query: "@day/string()" }
		XmlRole { name: "date"; query: "@date/string()" }
		XmlRole { name: "low"; query: "@low/string()" }
		XmlRole { name: "high"; query: "@high/string()" }
		XmlRole { name: "text"; query: "@text/string()" }
	}

参考文档：https://msdn.microsoft.com/zh-cn/library/ms190945(v=sql.105).aspx