Sort a List of Object in VB.NET

Question

I have a list of passengers(object) where it has a differents properties..

passenger.name
passenger.age
passenger.surname

And I want to sor

Answer 1

you must implement IComparer interface.

In this sample I've my custom object JSONReturn, I implement my class like this :

Friend Class JSONReturnComparer
    Implements IComparer(of JSONReturn)

    Public Function Compare(x As JSONReturn, y As JSONReturn) As Integer Implements    IComparer(Of JSONReturn).Compare
        Return String.Compare(x.Name, y.Name)
    End Function

End Class

I call my sort List method like this : alResult.Sort(new JSONReturnComparer())

Maybe it could help you

Answer 2

To sort by a property in the object, you have to specify a comparer or a method to get that property.

Using the List.Sort method:

theList.Sort(Function(x, y) x.age.CompareTo(y.age))

Using the OrderBy extension method:

theList = theList.OrderBy(Function(x) x.age).ToList()

Answer 3

If you need a custom string sort, you can create a function that returns a number based on the order you specify.

For example, I had pictures that I wanted to sort based on being front side or clasp. So I did the following:

Private Function sortpictures(s As String) As Integer
    If Regex.IsMatch(s, "FRONT") Then
        Return 0
    ElseIf Regex.IsMatch(s, "SIDE") Then
        Return 1
    ElseIf Regex.IsMatch(s, "CLASP") Then
        Return 2
    Else
        Return 3
    End If
End Function

Then I call the sort function like this:

list.Sort(Function(elA As String, elB As String)
                  Return sortpictures(elA).CompareTo(sortpictures(elB))
              End Function)

Answer 4

try..

Dim sortedList = From entry In mylist Order By entry.name Ascending Select entry

mylist = sortedList.ToList