복잡한 개체의 여러 키를 사용하여 LINQ 쿼리를 강력하게 입력하는 방법

Question

강력하게 입력 할 수 있도록 LINQ 그룹화 쿼리에 사용되는 개체를 정의하는 방법을 알 수 없습니다.

두 개의 복잡한 개체를 키로 사용하는 그룹 쿼리를 작성했습니다. 쿼리가 작동하지만 반환 개체 형식을 선언 할 수 싶습니다. 나는 복잡한 유형이

... 나는 목록에서 수집하고이 복잡한 키를 기준으로 함께 그룹화하고있어

Public Class Student 
    Public Name As IndividualsName 
    Public EnrolledSchool As School 
    Public BirthHospital As BirthPlace 
    Public Grade As Integer 

    Public Sub New(ByVal name As IndividualsName, ByVal enrolledSchool As School, ByVal birthHospital As BirthPlace, ByVal grade As Integer) 
     Me.Name = name 
     Me.EnrolledSchool = enrolledSchool 
     Me.BirthHospital = birthHospital 
     Me.Grade = grade 
    End Sub 

End Class 

Public Class School 
    Inherits Location 


    Public Sub New(ByVal name As String, ByVal city As String, ByVal state As String) 
     MyBase.New(name, city, state) 
    End Sub 

    Public Shared Function GetMyHS() As School 
     Return New School("My High School", "My City", "My State") 
    End Function 
    Public Shared Function GetYourHS() As School 
     Return New School("Your High School", "Your City", "Your State") 
    End Function 
    Public Shared Function GetMyElementry() As School 
     Return New School("My Elementary", "My City", "My State") 
    End Function 
    Public Shared Function GetMyMiddleSchool() As School 
     Return New School("My Middle School", "My City", "My State") 
    End Function 

End Class 

Public Class IndividualsName 
    Public First As String 
    Public Last As String 

    Public Sub New(ByVal first As String, ByVal last As String) 
     Me.First = first 
     Me.Last = last 
    End Sub 

    Public Overrides Function ToString() As String 
     Return First & " " & Last 
    End Function 
End Class 

Public Class BirthPlace 
    Inherits Location 

    Public Sub New(ByVal name As String, ByVal city As String, ByVal state As String) 
     MyBase.New(name, city, state) 
    End Sub 

    Public Shared Function GetMyHospital() As BirthPlace 
     Return New BirthPlace("My General Hospital", "My City", "My State") 
    End Function 

    Public Shared Function GetYourHospital() As BirthPlace 
     Return New BirthPlace("Your General Hospital", "Your City", "Your State") 
    End Function 
End Class 

Public Class Location 
    Public Name As String 
    Public City As String 
    Public State As String 

    Public Sub New(ByVal name As String, ByVal city As String, ByVal state As String) 
     Me.Name = name 
     Me.City = city 
     Me.State = state 
    End Sub 

    Public Overrides Function Equals(ByVal obj As Object) As Boolean 
     Return Me.GetHashCode = obj.GetHashCode 
    End Function 

    Public Overrides Function GetHashCode() As Integer 
     Dim returnValue As Integer 
     returnValue = Me.Name.GetHashCode() Xor Me.City.GetHashCode() Xor Me.State.GetHashCode() 
     Return returnValue 
    End Function 

End Class 

.

Sub Main() 

    Dim students As List(Of Student) = New List(Of Student) 

    students.Add(New Student(New IndividualsName("Bill", "Jones"), School.GetMyHS(), BirthPlace.GetMyHospital(), 9)) 
    students.Add(New Student(New IndividualsName("George", "Jamesen"), School.GetMyHS(), BirthPlace.GetMyHospital(), 11)) 
    students.Add(New Student(New IndividualsName("Chris", "McCartney"), School.GetYourHS(), BirthPlace.GetMyHospital(), 9)) 
    students.Add(New Student(New IndividualsName("Sara", "Smith"), School.GetMyMiddleSchool(), BirthPlace.GetMyHospital(), 7)) 
    students.Add(New Student(New IndividualsName("Josh", "Jefferies"), School.GetMyMiddleSchool(), BirthPlace.GetYourHospital(), 8)) 
    students.Add(New Student(New IndividualsName("Mel", "Tompson"), School.GetMyHS(), BirthPlace.GetMyHospital(), 12)) 
    students.Add(New Student(New IndividualsName("Jill", "Schmidt"), School.GetYourHS(), BirthPlace.GetMyHospital(), 10)) 
    students.Add(New Student(New IndividualsName("Beth", "Taylor"), School.GetMyElementry(), BirthPlace.GetMyHospital(), 5)) 
    students.Add(New Student(New IndividualsName("Mark", "Thatcher"), School.GetMyElementry(), BirthPlace.GetMyHospital(), 4)) 
    students.Add(New Student(New IndividualsName("Tom", "Jones"), School.GetMyHS(), BirthPlace.GetYourHospital(), 9)) 
    students.Add(New Student(New IndividualsName("Kevin", "Woo"), School.GetMyMiddleSchool(), BirthPlace.GetYourHospital(), 7)) 

    Dim groupedQuery 'As IEnumerable(Of IGrouping()) 
    groupedQuery = From student In students _ 
        Group student By student.EnrolledSchool, student.BirthHospital Into Group _ 
       Select EnrolledSchool, BirthHospital, StudentGroup = Group 

    For Each groupItem In groupedQuery 
     Console.WriteLine(String.Format("School: {0}, Birth Place: {1}", groupItem.EnrolledSchool.Name, groupItem.BirthHospital.Name)) 
     'Console.WriteLine(String.Format("Group Item is type {0}.", groupItem.GetType())) 

     For Each item As Student In groupItem.StudentGroup 
      Console.WriteLine(String.Format("Name: {0} - Grade: {1}", item.Name.ToString(), item.Grade.ToString())) 
     Next 

    Next 
End Sub 

모든 것이 작동하지만 데이터 수집을 처리 할 때 모든 것이 익명으로 선언됩니다. 특히 그룹화 된 목록을 만드는 개체가 하나의 어셈블리에 있고 웹 서비스 및 웹 사이트에서 사용되는 것이 매우 귀찮습니다.

정말 강력하게 반환되는 IEnumberable을 입력 할 수 있기를 원하지만 내 IGrouping interface을 선언하는 방법을 알 수 없습니다.

내가 좋아하는 내 데이터 구조를 횡단 할 수 있어야한다 ...

Dim groupedQuery As IEnumerable(Of IGrouping(Of IDoNotKnowHowToDeclareMyComplexKey, Student)) 
    groupedQuery = From student In students _ 
        Group student By student.EnrolledSchool, student.BirthHospital Into Group _ 
       Select EnrolledSchool, BirthHospital, StudentGroup = Group 

    For Each groupItem As IGrouping(Of IDoNotKnowHowToDeclareMyComplexKey, Student) In groupedQuery 
     Console.WriteLine(String.Format("School: {0}, Birth Place: {1}", groupItem.Key.Name) 
     For Each item As Student In groupItem 
      Console.WriteLine(String.Format("Name: {0} - Grade: {1}", item.Name.ToString(), item.Grade.ToString())) 
     Next 

    Next 

하지만 지금까지 내 IGrouping 유형을 선언하는 방법을 알아낼 수 없었다.

Answer 1

, 새로운 클래스를 만들 :

Public Class SomeName 
    Public EnrolledSchool As School 
    Public BirthHospital As BirthPlace 
    Public StudentGroup As IEnumerable(Of Student) 
End Class 

그런 다음 그것을 사용 그룹화 동안 :

Dim result As IEnumerable(Of SomeName) 
result = (From student In students _ 
Group student By student.EnrolledSchool, student.BirthHospital Into Group _ 
Select New SomeName With {.EnrolledSchool = EnrolledSchool, .BirthHospital = BirthHospital, .StudentGroup = Group}) 

당신이 어떤 문제가있을 경우, 여기에 장소 코드 및 오류 당신이 얻을.

Answer 2

무언가가 익명 인 경우 정의를 통해 이름으로 부를 수 없습니다.

복잡한 키 유형을 나타내는 새 클래스를 만들어 익명 형식 대신 사용해야합니다. 브라이언 말했듯이