Question

鉴于以下XML：

<notes>
    <note>
        <to>Rove</to>
        <from>Jan</from>
        <heading>Reminder</heading>
        <body>Don't forget me this weekend!</body>
    </note>
    <note>
        <to>Joe</to>
        <from>Black</from>
        <heading>Reminder</heading>
        <body>Don't forget me this weekend!</body>
    </note>
    <note>
        <to>Wako</to>
        <from>Halo</from>
        <heading>Reminder</heading>
        <body>Don't forget me this weekend!</body>
    </note>
    <note>
        <to>Bill</to>
        <from>Job</from>
        <heading>Reminder</heading>
        <body>Don't forget me this weekend!</body>
    </note>
</notes>

使用XPath和C＃，如何设置以下节点：

从{fromValue}到{toValue}

从{fromValue}到{toValue}

从{fromValue}到{toValue}

从{fromValue}到{toValue}

到目前为止我尝试的内容：

const string xmlStr =
                    @"<notes>
                        <note>
                           ......</notes>";



using (var stream = new StringReader(xmlStr))
{
    var document = new XPathDocument(stream);
    XPathNavigator navigator = document.CreateNavigator();

    XPathNodeIterator nodes = navigator.Select("/notes/note/from");
    if (nodes.MoveNext())
    {
        XPathNavigator nodesNavigator = nodes.Current;

        XPathNodeIterator nodesText =
            nodesNavigator.SelectDescendants(XPathNodeType.Text, false);

        while (nodesText.MoveNext())
        {
           var currentValue = nodesText.Current.Value;
           Console.WriteLine("From: {0}, To: {1}", currentValue, currentValue);
        }
    }
}

我明白了：

From: Jan, To: Jan
From: Black, To: Black
...

Answer 1

有许多方法可以在C＃中执行您所要求的操作，而不一定涉及XPath。

最简单的想法是

foreach (var node in XDocument.Parse(xmlStr).Root.Elements("note")) {
    Console.WriteLine("from: {0}; to: {1}",
                      node.Element("from").Value,
                      node.Element("to").Value);
}

这会产生输出

from: Jan; to: Rove
from: Black; to: Joe
from: Halo; to: Wako
from: Job; to: Bill

除非你被绑定到.NET 2.0（没有System.Xml.Linq），或者有其他要求，否则我会从这开始。

Answer 2

您可以使用LINQ to XML作为解决问题的优雅方式。

var document = XDocument.Parse(xml);
var xElements = document.Descendants("note");
foreach (var element in xElements)
{
    Console.WriteLine(
        "From {0} To {1}", 
        (string)element.Element("from"), 
        (string)element.Element("to"));
}

如何使用XPath从XML获取特定节点？

2 个答案: