Make a linq query distict by two fields [duplicate] - linq

Question

Looking at Select distinct by two properties in a list it is possible to use the DistinctBy extensionmethod with two properties. I tried to convert this to vb.net, but I'm not getting the expected results
Test Class:
Public Class Test
Public Property Id As Integer
Public Property Name As String
Public Overrides Function ToString() As String
Return Id & " - " & Name
End Function
End Class
Test Method:
Private Sub RunTest()
Dim TestList As New List(Of Test)
TestList.Add(New Test() With {.Id = 1, .Name = "A"})
TestList.Add(New Test() With {.Id = 2, .Name = "A"})
TestList.Add(New Test() With {.Id = 3, .Name = "A"})
TestList.Add(New Test() With {.Id = 1, .Name = "A"})
TestList.Add(New Test() With {.Id = 1, .Name = "B"})
TestList.Add(New Test() With {.Id = 1, .Name = "A"})
Dim Result As IEnumerable(Of Test)
Result = TestList.DistinctBy(Function(element) element.Id)
'1 - A
'2 - A
'3 - A
Result = TestList.DistinctBy(Function(element) element.Name)
'1 - A
'1 - B
Result = TestList.DistinctBy(Function(element) New With {element.Id, element.Name})
'1 - A
'2 - A
'3 - A
'1 - A
'1 - B
'1 - A
'Expected:
'1 - A
'2 - A
'3 - A
'1 - B
End Sub
Is this at all possible in vb.net using anonymous types?
Doing something like this:
Result = TestList.DistinctBy(Function(element) element.Id & "-" & element.Name)
is working, therefore I'm guessing I'm missing something with equality in anonymous types here.

Answer 1

You need to write Key before property. like
New With {Key element.Id, Key element.Name} in VB.
So,
Result = TestList.DistinctBy(Function(element) New With {Key element.Id, Key element.Name})
See the documentation for anonymous types in VB for more details.