book.xml
<?xml?version="1.0"?encoding="utf-8"??> <bookstore>
??<book?category="COOKING"> <title?lang="en">Everyday?Italian</title> <author>Giada?De?Laurentiis</author> <year>2005</year> <price>30.00</price> </book>
??<book?category="CHILDREN"> <title?lang="en">Harry?Potter</title> <author>J?K.?Rowling</author> <year>2005</year> <price>29.99</price> </book>
??<book?category="WEB"> <title?lang="en">XQuery?Kick?Start</title> <author>James?McGovern</author> <author>Per?Bothner</author> <author>Kurt?Cagle</author> <author>James?Linn</author> <author>Vaidyanathan?Nagarajan</author> <year>2003</year> <price>49.99</price> </book>
??<book?category="WEB"> <title?lang="en">Learning?XML</title> <author>Erik?T.?Ray</author> <year>2003</year> <price>39.95</price> </book>
</bookstore>
c#代碼： //判斷是否存在title的取值為：'Harry?Potter'的節點存在????????
??????????? Stopwatch watch = Stopwatch.StartNew();
??????????? var xmlDoc2 = new XmlDocument();
??????????? xmlDoc2.Load(@"book.xml");??????
??????????? var titleTextExpr4 = "/bookstore/book[title='Harry Potter']/title";
??????????? var titleTextNodes4 = xmlDoc2.SelectNodes(titleTextExpr4);????????????? ?
??????????? Console.WriteLine("XPath表達式為 /bookstore/book[title='Harry Potter']/title，節點數為：" + titleTextNodes4.Count);
??????????? if(titleTextNodes4.Count>0)
??????????? {
??????????????? Console.WriteLine("title='Harry Potter'的節點存在");
??????????? }
??????????? else
??????????? {
??????????????? Console.WriteLine("title='Harry Potter'的節點不存在");
??????????? }??????????
??????????? watch.Stop();
??????????? Console.WriteLine("take times(ms)="+watch.ElapsedMilliseconds);

轉載于:https://www.cnblogs.com/wangqiideal/p/4600178.html

創作挑戰賽新人創作獎勵來咯，堅持創作打卡瓜分現金大獎

總結

以上是生活随笔為你收集整理的.net中使用XPath语言在xml中判断是否存在节点值的方法的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。