根据条件从XML中删除元素 [英] Remove element from XML based on condition

问题描述

以下是我的XML结构。



XML

Hi,

Below is the XML structure I have.

XML

<Info>
<Details>
<ID>user</ID>
<StartDate>23-10-2016</StartDate>
<EndDate>22-10-2016</EndDate>
</Details>
<Details>
<ID>user1</ID>
<StartDate>23-10-2016</StartDate>
<EndDate>24-10-2016</EndDate>
</Details>
<Details>
<ID>user2</ID>
<StartDate>23-10-2016</StartDate>
<EndDate>22-11-2016</EndDate>
</Details>
</Info>

Now I need to compare the EndDate node with today's date. If EndDate is lesser than today's date then I need to remove the whole contents of Details. For Ex: Let's assume strDate a string has today's date.

The below code takes all the values of EndDate and now how can I compare the string value and loop through xml elements and delete them.

Now this whole portion should be deleted as of comparing with todays date.

<Details>
<ID>user</ID>
<StartDate>23-10-2016</StartDate>
<EndDate>22-10-2016</EndDate>
</Details>

真的很感激任何建议。



我尝试过：



object [] arr = xDos.Descendants（Details）。Elements（EndDate）。

Select（element = element.Value ）.ToArray（）;

Really appreciate any suggestions on this.

What I have tried:

object[] arr = xDos.Descendants("Details").Elements("EndDate").
Select(element = element.Value).ToArray();

推荐答案

如果XML不包含EndDate节点或者EndDate节点不是有效日期，此解决方案将起作用但可能会失败（我已将其创建为单元测试）[这可能是通过某种形式的XSD验证来缓解，其中EndDate是强制日期]

This solution will will work but could fail if the XML either does not contain the EndDate node or the EndDate node is not a valid Date (I have created it as a Unit Test) [This could be mitigated by some form of XSD validation of the XML where the EndDate is a Mandatory Date]

public void TestMethod1()
        {
            var todaysDate1 = new DateTime(2001, 10, 30); // no nodes selected
            var todaysDate2 = new DateTime(2016, 10, 28); // one node selected
            var todaysDate3 = new DateTime(2016, 10, 30); // 2 nodes selected
            var todaysDate4 = new DateTime(2016, 12, 25); // 3 nodes selected

            var xmlData ="<Info><Details><ID>user</ID><StartDate>23-10-2016</StartDate><EndDate>22-10-2016</EndDate></Details><Details><ID>user1</ID><StartDate>23-10-2016</StartDate><EndDate>29-10-2016</EndDate></Details><Details><ID>user2</ID><StartDate>23-10-2016</StartDate><EndDate>22-11-2016</EndDate></Details></Info>";
            XDocument xdoc = XDocument.Parse(xmlData);

            var nodes = xdoc.Descendants("Details");
            nodes.Where(x => DateTime.Compare(DateTime.Parse(x.Element("EndDate").Value), todaysDate1) > 0).Remove();

            Assert.AreEqual(0, xdoc.Descendants("Details").Count());

            // Test 2
            xdoc = XDocument.Parse(xmlData);
            nodes = xdoc.Descendants("Details");
            nodes.Where(x => DateTime.Compare(DateTime.Parse(x.Element("EndDate").Value), todaysDate2) > 0).Remove();
            Assert.AreEqual(1, xdoc.Descendants("Details").Count());

            // Test 3
            xdoc = XDocument.Parse(xmlData);
            nodes = xdoc.Descendants("Details");
            nodes.Where(x => DateTime.Compare(DateTime.Parse(x.Element("EndDate").Value), todaysDate3) > 0).Remove();
            Assert.AreEqual(2, xdoc.Descendants("Details").Count());

            // Test 4
            xdoc = XDocument.Parse(xmlData);
            nodes = xdoc.Descendants("Details");
            nodes.Where(x => DateTime.Compare(DateTime.Parse(x.Element("EndDate").Value), todaysDate4) > 0).Remove();
            Assert.AreEqual(3, xdoc.Descendants("Details").Count());
        }

Null异常的问题困扰着我 - 但是感谢Resharper这里有另一种选择（我无法解决这个问题）日期问题）

The issue of the Null exception bothered me - but thanks to Resharper here is an alternative (I have not been able to resolved the invalid date issue)

nodes.Where(x =>
                {
                    var element = x.Element("EndDate");
                    return element != null && DateTime.Compare(DateTime.Parse(element.Value), todaysDate1) > 0;
                }).Remove();

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