VB6 -> VB.Net collection classes

[Guest Imogen]

Hi, when using VB6 I used to use the collection object and put in in a wrapper to facilitate my own collections

 

e.g.

 

collection: wrapper around VB's collection class

 

object: my own custom object.

 

How do I achieve this in .Net, including exposing the enumeration.

 

thanks Imogen

[Thinker]

You have to inherit one of the System.Collections classes and

extend it however you need. But, with all the options available

in the System.Collections namespace, it is hard to believe you

would need to extend one. There is an ArrayList, BitArray,

Dictionary, Hashtable, Queue, SortedList, and Stack. It is a huge

improvement over VB6.

[Merrion]

To make a type safe collection, inherit from the DictionaryBase collection and overload the properties Item, Add and Contains e.g.:

 

Public Class Vehicle
 Public LicencePlate As String '\\This is unique...
 Public Make As String
End Class

Public Class VehiclesDictionary
  Inherits Collections.DictionaryBase

  Public Overloads Property Item(ByVal LicencePlate As String) As Vehicle
       Get
           Return CType(dictionary.Item(LicencePlate), Vehicle)
       End Get
       Set (Byval Value As Vehilce)
               dictionary.Item(Value.LicencePlate) = Value
        End Set

  End Property


End Class

 

Hope this is useful,

Duncan

[divil]

If you just need a strongly-typed collection, you can inherit from CollectionBase.