如何使用 linq 从 xml 文档中删除重复项？答案

【问题标题】：How do i remove duplicates from xml doc using linq?如何使用 linq 从 xml 文档中删除重复项？
【发布时间】：2021-08-13 02:32:07
【问题描述】：

我有以下代码，需要删除重复的 Id 并将结果作为字符串返回？

scheduledCustomerJourneysXml 是一个包含以下 xml 的字符串变量：

XDocument doc = XDocument.Parse(scheduledCustomerJourneysXml);


<ScheduledCustomerJourneys>
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534454" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534455" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534455" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538020" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538020" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538020" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538020" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="531228" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534457" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="526977" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="526978" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538023" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534459" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534459" />
</ScheduledCustomerJourneys>

【问题讨论】：

到目前为止你尝试了什么？

标签： c# xml linq

【解决方案1】：

您可以使用GroupBy 查找重复项，然后删除内存中的重复项并返回字符串表示形式：

doc.Descendants("ScheduledCustomerJourney")
        .GroupBy(x => x.Attribute("ScheduledCustomerJourneyId").Value)
        .SelectMany(x => x.Key == string.Empty ? x : x.Skip(1))
        .Remove();

Console.WriteLine(doc.ToString());

输出：

<ScheduledCustomerJourneys>
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534454" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534455" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538020" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="531228" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534457" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="526977" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="526978" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="538023" />
  <ScheduledCustomerJourney ScheduledCustomerJourneyId="534459" />
</ScheduledCustomerJourneys>

见working DEMO Fiddle

【讨论】：