如何编写嵌套的 Linq To Xml 查询

Question

你好，我正在编写一款医学研究应用程序。用户需要输入性别、年龄和其他一些值，这些值将计算成一个结果值。

现在我有一个XML文件，其中包含有关结果的一些信息，这些信息与年龄、性别和结果值的组合有关，我想打印出测试结果的描述（在哪个组中）。需要注意的一点是，我必须处理值范围，这意味着实际值位于低部和高部之间... 我有三个组...

好的，这是我的XML文件：

<?xml version="1.0" encoding="iso-8859-1"?>
 <Result>
        <ID>1</ID>
        <Description>You belong to Group 1</Description>
        <Genders>
            <Gender type="female">
                <Ages>
                    <Age low="18" high="24">
                        <ResultValue low="0" high="19"/>
                    </Age>
                    <Age low="25" high="34">
                        <ResultValue low="0" high="20"/>
                    </Age>
                    <Age low="35" high="44">
                        <ResultValue low="0" high="21"/>
                    </Age>
                    <Age low="45" high="54">
                        <ResultValue low="0" high="22"/>
                    </Age>
                    <Age low="55" high="64">
                        <ResultValue low="0" high="23"/>
                    </Age>
                    <Age low="65" high="110">
                        <ResultValue low="0" high="24"/>
                    </Age>
                </Ages>
            </Gender>
            <Gender type="male">
                <Ages>
                    <Age low="18" high="24">
                        <ResultValue low="0" high="19"/>
                    </Age>
                    <Age low="25" high="34">
                        <ResultValue low="0" high="20"/>
                    </Age>
                    <Age low="35" high="44">
                        <ResultValue low="0" high="21"/>
                    </Age>
                    <Age low="45" high="54">
                        <ResultValue low="0" high="22"/>
                    </Age>
                    <Age low="55" high="64">
                        <ResultValue low="0" high="23"/>
                    </Age>
                    <Age low="65" high="110">
                        <ResultValue low="0" high="24"/>
                    </Age>
                </Ages>
            </Gender>
        </Genders>
    </Result>
    <Result>
        <ID>2</ID>
        <Description>You belong to Group 2</Description>
        <Genders>
            <Gender type="female">
                <Ages>
                    <Age low="18" high="24">
                        <ResultValue low="19" high="24"/>
                    </Age>
                    <Age low="25" high="34">
                        <ResultValue low="20" high="25"/>

                    </Age>
                    <Age low="35" high="44">
                        <ResultValue low="21" high="26"/>
                    </Age>
                    <Age low="45" high="54">
                        <ResultValue low="22" high="27"/>
                    </Age>
                    <Age low="55" high="64">
                        <ResultValue low="23" high="28"/>
                    </Age>
                    <Age low="65" high="110">
                        <ResultValue low="24" high="29"/>
                    </Age>
                </Ages>
            </Gender>
            <Gender type="male">
                <Ages>
                    <Age low="18" high="24">
                        <ResultValue low="19" high="24"/>
                    </Age>
                    <Age low="25" high="34">
                        <ResultValue low="20" high="25"/>
                    </Age>
                    <Age low="35" high="44">
                        <ResultValue low="21" high="26"/>
                    </Age>
                    <Age low="45" high="54">
                        <ResultValue low="22" high="27"/>
                    </Age>
                    <Age low="55" high="64">
                        <ResultValue low="23" high="28"/>
                    </Age>
                    <Age low="65" high="110">
                        <ResultValue low="24" high="29"/>
                    </Age>
                </Ages>
            </Gender>
        </Genders>
    </Result>
    <Result>
        <ID>3</ID>
        <Description>You belong to group 3</Description>
        <Genders>
            <Gender type="female">
                <Ages>
                    <Age low="18" high="24">
                        <ResultValue low="24" high="29"/>
                    </Age>
                    <Age low="25" high="34">
                        <ResultValue low="25" high="30"/>

                    </Age>
                    <Age low="35" high="44">
                        <ResultValue low="26" high="31"/>
                    </Age>
                    <Age low="45" high="54">
                        <ResultValue low="27" high="32"/>
                    </Age>
                    <Age low="55" high="64">
                        <ResultValue low="28" high="33"/>
                    </Age>
                    <Age low="65" high="110">
                        <ResultValue low="29" high="34"/>
                    </Age>
                </Ages>
            </Gender>
            <Gender type="male">
                <Ages>
                    <Age low="18" high="24">
                        <ResultValue low="24" high="29"/>
                    </Age>
                    <Age low="25" high="34">
                        <ResultValue low="25" high="30"/>
                    </Age>
                    <Age low="35" high="44">
                        <ResultValue low="26" high="31"/>
                    </Age>
                    <Age low="45" high="54">
                        <ResultValue low="27" high="32"/>
                    </Age>
                    <Age low="55" high="64">
                        <ResultValue low="28" high="33"/>
                    </Age>
                    <Age low="65" high="110">
                        <ResultValue low="29" high="34"/>
                    </Age>
                </Ages>
            </Gender>
        </Genders>   
    </Result>

如果我有以下条件：

性别="女性"

年龄=29

结果值=17

这个被试者肯定属于第一组，我想打印出匹配的描述...

但是我一直无法让它工作...

我正在寻找C#的解决方案...任何帮助都将不胜感激！

- Felix

---

你是在寻找VB.Net LINQ to XML查询还是C#的呢？答案截然不同。 - JaredPar

哦，抱歉！我正在寻找一个C#的解决方案... - Felix

Answer 1

像这样的内容吗？

XElement myElement = XElement.Parse(xmlstring);

int resultValue = 17;
int age = 26;
string genderValue = "female";

IEnumerable<string> query =
    myElement.Descendants("ResultValue")
        .Where(rv => ((int)rv.Attribute("low")) <= resultValue)
        .Where(rv => ((int)rv.Attribute("high")) >= resultValue)
        .Where(rv => rv.Ancestors("Age")
            .Any(a => ((int) a.Attribute("low")) <= age && ((int) a.Attribute("high")) >= age)
        )
       .Where(rv => ((string)rv.Ancestors("Gender").Single().Attribute("type")) == genderValue)
       .Select(rv => rv.Ancestors("Result").Single().Element("Description").Value);

    foreach (string x in query)
        Console.WriteLine(x);

这个想法是你可以想象一个行列形状，其中每一行都是一个ResultValue。每个结果值都有一个父级年龄、一个父级性别和一个父级结果。

ResultValue.Low ResultValue.High Age.Low Age.High Gender.Type Result.Description

实际上，可以将上述xml投影到该形状中：

        var query2 = myElement.Descendants("ResultValue")
            .Select(rv => new 
            {
                ResultValue = rv,
                Age = rv.Ancestors("Age"),
                Gender = rv.Ancestors("Gender"),
                Result = rv.Ancestors("Result")
            })
            .Select(x => new XElement("Data",
            new XAttribute("ResultValue.Low", (int)x.ResultValue.Attribute("low")),
            new XAttribute("ResultValue.High", (int)x.ResultValue.Attribute("high")),
            new XAttribute("Age.Low", (int)x.Age.Attributes("low").Single()),
            new XAttribute("Age.High", (int)x.Age.Attributes("high").Single()),
            new XAttribute("Gender.Type", (string) x.Gender.Attributes("type").Single()),
            new XAttribute("Result.Description", (string) x.Result.Elements("Description").Single())
            ));
        foreach (XElement x in query2)
            Console.WriteLine(x);

- David B