如何使用linq将对象扩展为基本属性 [英] How to expand object to primitive properties using linq

问题描述

假设我有以下课程:

public class StudentTeacher
{
public Student Student {get; set;}   
public Teacher Teacher {get; set;}   
public int OverlappingClasses {get; set;}
}

现在，在我的代码中，我有一个对象列表.

Now, in my code I have a list of objects.

List<StudentTeacher> studentTeacher = GetStudentTeachers();   

现在，我需要选择所有属性作为属性而不是对象.

Now, I need to select all properties as properties not as objects.

因此，例如，我可以这样做:studentTeacher.Select(x=>x.Student)它将返回对象列表(IEnumerable).

So, for example, I can do this: studentTeacher.Select(x=>x.Student) and it will return a list of objects (IEnumerable).

但是当我选择多个属性时，即studentTeacher.Select(x => new {x.Student，x.Teacher}).ToList()，返回类型为IEnumerable {Anonymous {Student, Teacher}}

But when I select multiple properties, i.e. studentTeacher.Select(x=> new {x.Student, x.Teacher}).ToList() the return type is IEnumerable {Anonymous {Student, Teacher}}

如何，我可以使用仅具有属性的简单匿名类型来代替这种复杂的匿名类型. (因此，它将为Anonymous{StudentID, StudentName, StudentLastName, TeacherID, TeahcerName, TeacherLastName, etc.})

How, instead of this complex anonymous type I can have a simple anonymous type with properties only. (So, it will be Anonymous{StudentID, StudentName, StudentLastName, TeacherID, TeahcerName, TeacherLastName, etc.})

一种方法是通过在select子句中显式指定所有属性，但是在我的特殊用例中，我在每个对象中拥有> 30个属性，而属性的总数为> 100.)

One way to do this is by explicitly specifying all properties in the select clause but in my particular use case I have >30 properties in each object and the total # of properties is >100.)

推荐答案

我认为这是您要尝试做的事情:

I think this is what you're trying to do:

    public class Student
    {
        public int StudentId
        {
            get;
            set;
        } = 1;

        public string StudentName
        {
            get;
            set;
        } = "Name";
    }

    public class Teacher
    {
        public int TeacherId
        {
            get;
            set;
        } = 666;

        public string TeacherName
        {
            get;
            set;
        } = "TeacherName";
    }

    public class StudentTeacher
    {
        public Student Student
        {
            get;
        } = new Student();

        public Teacher Teacher
        {
            get;
        } = new Teacher();
    }

    public static dynamic GetAnonType(Student student, Teacher teacher)
    {
        var propertyNamesAndPropertiesStudent = student.GetType().GetProperties().Select(item => Tuple.Create($"{nameof(Student)}{item.Name}", item.GetMethod.Invoke(student, null)));
        var propertyNamesAndPropertiesTeacher = teacher.GetType().GetProperties().Select(item => Tuple.Create($"{nameof(Teacher)}{item.Name}", item.GetMethod.Invoke(teacher, null)));
        dynamic sampleObject = new ExpandoObject();
        foreach(var propertyNamePropertyValuePair in propertyNamesAndPropertiesStudent)
        {
            ((IDictionary<string, object>)sampleObject).Add(propertyNamePropertyValuePair.Item1, propertyNamePropertyValuePair.Item2);
        }

        foreach(var propertyNamePropertyValuePair in propertyNamesAndPropertiesTeacher)
        {
            ((IDictionary<string, object>)sampleObject).Add(propertyNamePropertyValuePair.Item1, propertyNamePropertyValuePair.Item2);
        }

        return sampleObject;
    }

您可以这样称呼:

        var studentTeachers = new List<StudentTeacher> {new StudentTeacher()};
        var anonTypes = studentTeachers.Select(item => GetAnonType(item.Student, item.Teacher));

anonTypes将是一个匿名类型的枚举，其成员为StudentId，StudentName，TeacherId，TeacherName.这应该缩放到更大的对象.

anonTypes will be an enumerable of anonymous types with members StudentId, StudentName, TeacherId, TeacherName. This should scale to larger objects.

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