企业官网建设流程全解析

1

2

3

4

5

6

7

8

// 基础示例

var lists =newList<List<int>> {

newList<int> { 1, 2, 3 },

newList<int> { 4, 5, 6 }

};

var flattened = lists.SelectMany(x => x);

// 结果: [1, 2, 3, 4, 5, 6]

1

2

var result = lists.SelectMany((list, index) =>

list.Select(item => $"列表{index}: {item}"));

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

publicclassStudent

{

publicstringName {get;set; }

publicList<Course> Courses {get;set; }

}

// 获取所有学生的所有课程

var allCourses = students.SelectMany(s => s.Courses);

// 带学生信息的课程列表

var studentCourses = students.SelectMany(

student => student.Courses,

(student, course) =>new{

StudentName = student.Name,

CourseName = course.Name

}

);

1

2

3

string[] words = {"Hello","World"};

var letters = words.SelectMany(word => word.ToLower());

// 结果: ['h','e','l','l','o','w','o','r','l','d']

1

2

3

4

5

6

7

// 方法语法

var result = students.SelectMany(s => s.Courses);

// 等价的查询语法

var result = from studentinstudents

from courseinstudent.Courses

select course;

1

2

3

4

5

6

7

var result = students.SelectMany(

student => student.Courses.Where(c => c.Credits > 3),

(student, course) =>new{

Student = student.Name,

Course = course.Name,

Credits = course.Credits

});

1

2

3

4

var departments =newList<Department>();

var result = departments

.SelectMany(d => d.Teams)

.SelectMany(t => t.Employees);

1

2

3

// 处理可能为null的集合

var result = students.SelectMany(s =>

s.Courses ?? Enumerable.Empty<Course>());