如何使用 XPath 获取 XML 节点的属性值

本文关键字:属性 节点 XML 何使用 XPath 获取 | 更新日期: 2023-09-27 18:33:10

这是我的脚本,但它只在控制台中打印空格。有人可以解释如何使用 xPath 从 XML 文件中获取属性值吗?

    XPathNavigator nav;
    XPathDocument docNav;
    XPathNodeIterator NodeIter;
    XmlNamespaceManager ns;
    Int32 elementCount;
    String windowName;
    private void Form1_Load(object sender, EventArgs e)
    {
        docNav = new XPathDocument("C:/BlueEyeMacro/DaMaGeX/Applications/WindowBuilder/GUI.xml");
        nav = docNav.CreateNavigator();
        ns = new XmlNamespaceManager(nav.NameTable); 
        elementCount = nav.Select("/GUI/window").Count;
        Console.WriteLine(elementCount);
        for (int i = 1; i <= elementCount; i++)
        {
            NodeIter = nav.Select("/GUI/window[@ID="+i+"]");
            windowName = NodeIter.Current.GetAttribute("name", ns.DefaultNamespace);
            Console.WriteLine("{0}", windowName);
        }
    }
}

XML 文件

<GUI>
<window ID="1" name="mainWindow" parent="0" type="0" text="My first window" options="Option 1;" actions="action 1;" exit="exit;" />
<window ID="2" name="secondWindow" parent="0" type="0" text="My second window" options="Option 1;" actions="action 1;" exit="exit;" />
<window ID="3" name="thirdWindow" parent="0" type="0" text="My third window" options="Option 1;" actions="action 1;" exit="exit;" /> </GUI>

如何使用 XPath 获取 XML 节点的属性值

我想

,你必须先调用NodeIter.MoveNext(),就像在这段代码中一样:

XPathNodeIterator nodesText = nodesNavigator.SelectDescendants(XPathNodeType.Text, false);
while (nodesText.MoveNext())
{
    Console.Write(nodesText.Current.Name);
    Console.WriteLine(nodesText.Current.Value);
}
可以直接

获取属性的字符串值:

    for (int i = 1; i <= elementCount; i++) 
    { 
     // This obtains the value of the @name attribute directly
     string val = 
               nav.Evaluate("string(/GUI/window[@ID='"+i+"']/@name)") as string;                
     Console.WriteLine(val); 
    }

您还可以修改代码以执行此操作:

    for (int i = 1; i <= elementCount; i++) 
    { 
        var NodeIter = nav.SelectSingleNode("/GUI/window[@ID='"+i+"']/@name"); //This selects the @name attribute directly
        Console.WriteLine("{0}", NodeIter.Value); 
    }

鉴于您是通过唯一 id 标识节点,SelectSingleNode 更适合您尝试执行的操作。