Question

ok, maybe it’s not a method exactly. here’s what I’d like to do:

Private _Columns As ArrayList
Public Property Columns() As ArrayList
    Get
       Return _Columns
    End Get
    Set(Cols As ArrayList)
       _Columns = Cols
    End Set
    Set(Cols As MyOwnList)
       _Columns = New ArrayList
       For Each o As MyObj in Cols
          _Columns.Add(o.Column)
       Next
    End Set
End Property

which would allow me to conveniently set the property by assigning to it various kinds of collection types… except, I can’t do it because apparently the Set method has to take an argument of the type of the property itself… I get the complaint:

‘Set’ parameter must have the same type as the containing property

is there a way to do this?

Answer 1

It’s not really overloading but the following could offer a (temporary) workaround:

Private Cols As ArrayList
Public Property Columns() As ArrayList
    Get
        Return _Columns
    End Get
    Set(Cols As ArrayList)
        _Columns = Cols
    End Set
End Property

Public WriteOnly Property SpecializedColumns() As MyOwnList
    Set(value As MyOwnList)
        Dim list As New ArrayList
        For Each o As MyObj In value
            list.Add(o.Column)
        Next
        Columns = list
    End Set
End Property

I think this is as close as you can get to real overloaded properties…

EDIT

I believe the proper way to do what you’re trying to achieve is to define a ToArrayList() method on your MyOwnList class.

Public Function ToArrayList()
    Dim list As New ArrayList

    For Each o As MyObj In Me.Items
        list.Add(o.Column)
    Next

    Return list
End Function

and set your property like this:

    Columns = theMyOwnListObject.ToArrayList

If you don’t have access to the source code of the class, you can still achieve this through extension methods.