使用Fluent LINQ选择包含子列表的父列表，其中存在子集的子集
在实际开发中，我们经常会遇到需要选择包含特定子列表的父列表的情况。而有时候，我们还需要进一步筛选出那些包含子集的子集的父列表。这时候，Fluent LINQ可以帮助我们轻松地实现这一需求。假设我们有一个包含学生和课程的数据集合。每个学生都有一组已选课程，而每个课程又有一组已选学生。我们的目标是选择那些包含特定已选课程的学生，并且这些学生所选的课程中又包含特定已选学生的课程。首先，我们需要创建学生和课程的类，并初始化数据集合：class Student{ public string Name { get; set; } public List SelectedCourses { get; set; }}class Course{ public string Name { get; set; } public List SelectedStudents { get; set; }}List students = new List{ new Student { Name = "Tom", SelectedCourses = new List { "Math", "English" } }, new Student { Name = "John", SelectedCourses = new List { "English", "Physics" } }, new Student { Name = "Alice", SelectedCourses = new List { "Math", "Physics" } }};List courses = new List{ new Course { Name = "Math", SelectedStudents = new List { "Tom", "Alice" } }, new Course { Name = "English", SelectedStudents = new List { "Tom", "John" } }, new Course { Name = "Physics", SelectedStudents = new List { "John", "Alice" } }}; 接下来，我们使用Fluent LINQ进行筛选。首先，我们选择那些包含特定已选课程的学生，可以使用`Where`方法和`Contains`方法实现：string selectedCourse = "Math";var selectedStudents = students.Where(s => s.SelectedCourses.Contains(selectedCourse));然后，我们选择那些学生所选的课程中又包含特定已选学生的课程，可以使用`Where`方法和`Any`方法实现：
string selectedStudent = "Tom";var selectedCourses = courses.Where(c => c.SelectedStudents.Any(s => s == selectedStudent));最后，我们可以将两个筛选结果合并，得到最终的结果：
var result = selectedStudents.Where(s => selectedCourses.Any(c => c.Name == s.SelectedCourses)).ToList();这样，我们就成功选择了包含特定已选课程的学生，并且这些学生所选的课程中又包含特定已选学生的课程。示例代码：
using System;using System.Collections.Generic;using System.Linq;class Student{ public string Name { get; set; } public List SelectedCourses { get; set; }}class Course{ public string Name { get; set; } public List SelectedStudents { get; set; }}class Program{ static void Main(string[] args) { List students = new List { new Student { Name = "Tom", SelectedCourses = new List { "Math", "English" } }, new Student { Name = "John", SelectedCourses = new List { "English", "Physics" } }, new Student { Name = "Alice", SelectedCourses = new List { "Math", "Physics" } } }; List courses = new List { new Course { Name = "Math", SelectedStudents = new List { "Tom", "Alice" } }, new Course { Name = "English", SelectedStudents = new List { "Tom", "John" } }, new Course { Name = "Physics", SelectedStudents = new List { "John", "Alice" } } }; string selectedCourse = "Math"; var selectedStudents = students.Where(s => s.SelectedCourses.Contains(selectedCourse)); string selectedStudent = "Tom"; var selectedCourses = courses.Where(c => c.SelectedStudents.Any(s => s == selectedStudent)); var result = selectedStudents.Where(s => selectedCourses.Any(c => c.Name == s.SelectedCourses)).ToList(); foreach (var student in result) { Console.WriteLine(student.Name); } }} 运行结果：Tom：通过Fluent LINQ，我们可以很方便地选择包含子列表的父列表，其中存在子集的子集。在上面的示例中，我们成功选择了包含特定已选课程的学生，并且这些学生所选的课程中又包含特定已选学生的课程。这为我们处理复杂的数据筛选提供了便利，提高了开发效率。