VB.Net/Generics/Generic Class

Declare a generic type

<source lang="vbnet"> Public Class Car End Class Module Program

 Sub Main()
   Dim myCars As New List(Of Car)
   myCars.Add(New Car())
   Console.WriteLine(myCars.Count)
   Dim MyInts As New List(Of Integer)
   MyInts.Add(50)
   Dim val As Integer = MyInts.Count
   Console.WriteLine(MyInts.Count)
 End Sub

End Module

 </source>

Generic Class Demo

<source lang="vbnet"> Public Class MainClass

  Public Shared Sub Main()
       Dim talker1 As New GenericTalker(Of Dog)()
       talker1.Talker = New Dog()
       talker1.sayHello()
       Dim talker2 As New GenericTalker(Of Cat)()
       talker2.Talker = New Cat()
       talker2.sayHello()
  End Sub

End Class Public Class GenericTalker(Of T)

   Public Talker As T
   Public Sub SayHello()
       Dim helloWorld As String
       helloWorld = Talker.ToString()
       Console.WriteLine(helloWorld)
   End Sub

End Class Public Class Dog

   Public Overrides Function ToString() As String
       Return "Dog!"
   End Function

End Class Public Class Cat

   Public Overrides Function ToString() As String
       Return "Cat"
   End Function

End Class Public Class Mouse

   Public Overrides Function ToString() As String
       Return "Mouse"
   End Function

End Class Public Class Person

   Public Overrides Function ToString() As String
       Return "Person"
   End Function

End Class

 </source>

Generic List stores Generic Class

<source lang="vbnet"> Imports System.Collections Imports System.Collections.Generic Public Class MainClass

  Public Shared Sub Main()
       Dim custColl As New List(Of Customer)()
       Dim cust As New Customer("1", "Name")
       cust.AddItem(New Order(DateTime.Parse("10/01/2004"), "1", "N"))
       cust.AddItem(New Order(DateTime.Parse("10/03/2004"), "2", "X"))
       cust.AddItem(New Order(DateTime.Parse("10/07/2004"), "3", "P"))
       custColl.Add(cust)
       cust = New Customer("2", "name 1")
       cust.AddItem(New Order(DateTime.Parse("11/04/2004"), "6", "P"))
       cust.AddItem(New Order(DateTime.Parse("11/07/2004"), "8", "Y"))
       cust.AddItem(New Order(DateTime.Parse("12/12/2004"), "9", "K"))
       custColl.Add(cust)
       cust = New Customer("3", "Name 3")
       cust.AddItem(New Order(DateTime.Parse("10/01/2004"), "4", "W"))
       custColl.Add(cust)

       For custIdx As Int32 = 0 To (custColl.Count - 1)
           cust = custColl(custIdx)
           Console.Out.WriteLine("Customer-) ID: {0}, Name: {1}", cust.Id, cust.Name)
           Dim orders() As Order = cust.Items
           For orderIdx As Int32 = 0 To (orders.Length - 1)
               Dim ord As Order = orders(orderIdx)
               Console.Out.WriteLine("    Order-> Date: {0}, Item: {1}, Desc: {2}", ord.OrderDate, ord.ItemId, ord.Description)
           Next
       Next

       Dim empColl As New List(Of Employee)()
       Dim emp As New Employee("1", "R")
       empColl.Add(emp)
       emp = New Employee("2", "M")
       empColl.Add(emp)
       emp = New Employee("3", "B")
       emp.AddItem(New Employee("6", "S"))
       emp.AddItem(New Employee("7", "B"))
       emp.AddItem(New Employee("8", "T"))
       empColl.Add(emp)
       For mgrIdx As Int32 = 0 To (empColl.Count - 1)
           Dim manager As Employee = empColl(mgrIdx)
           Console.Out.WriteLine("Manager-) ID: {0}, Name: {1}", manager.Id, manager.Name)
           For idx As Int32 = 0 To (manager.Items.Length - 1)
               emp = manager.Items(idx)
               Console.Out.WriteLine("    Employee-) Id: {0}, Name: {1}", emp.Id, emp.Name)
           Next
       Next
  End Sub

End Class Public Class Customer

   Inherits Person(Of Order)
   Public Sub New(ByVal Id As String, ByVal Name As String)
       MyBase.New(Id, Name)
   End Sub

End Class

Public Class Employee

   Inherits Person(Of Employee)
   Public Sub New(ByVal Id As String, ByVal Name As String)
       MyBase.New(Id, Name)
   End Sub

End Class

Public Class Order

   Public OrderDate As DateTime
   Public ItemId As String
   Public Description As String
   Public Sub New(ByVal OrderDate As DateTime, ByVal ItemId As String, ByVal Description As String)
       Me.OrderDate = OrderDate
       Me.ItemId = ItemId
       Me.Description = Description
   End Sub

End Class

Public Class Person(Of T)

   Public Name As String
   Public Id As String
   Private _items As List(Of T)
   Public Sub New(ByVal Id As String, ByVal Name As String)
       Me.Id = Id
       Me.Name = Name
       Me._items = New List(Of T)
   End Sub
   Public ReadOnly Property Items() As T()
       Get
           Return Me._items.ToArray()
       End Get
   End Property
   Public Sub AddItem(ByVal newItem As T)
       Me._items.Add(newItem)
   End Sub

End Class

 </source>

Generic Point Structure

<source lang="vbnet">

Option Explicit On Option Strict On Module Program

 Sub Main()
   Dim intPt As New Point(Of Integer)(100, 100)
   Console.WriteLine(intPt.ToString())
   Dim dblPt As New Point(Of Double)(5.6, 3.23)
   Console.WriteLine(dblPt.ToString())
   Dim p1 As New Point(Of Integer)(10, 43)
   Dim p2 As New Point(Of Integer)(6, 987)
   Console.WriteLine(p1)
   Console.WriteLine(p2)
   Swap(Of Point(Of Integer))(p1, p2)
   Swap(p1, p2)
   Console.WriteLine(p1)
   Console.WriteLine(p2)
 End Sub
 Public Function Swap(Of T)(ByRef a As T, ByRef b As T) As T
   Console.WriteLine("T is a {0}.", GetType(T))
   Dim temp As T
   temp = a
   a = b
   b = temp
 End Function

End Module Public Structure Point(Of T)

 Private xPos, yPos As T
 Public Sub New(ByVal x As T, ByVal y As T)
   xPos = x : yPos = y
 End Sub
 Public Property X() As T
   Get
     Return xPos
   End Get
   Set(ByVal value As T)
     xPos = value
   End Set
 End Property
 Public Property Y() As T
   Get
     Return xPos
   End Get
   Set(ByVal value As T)
     yPos = value
   End Set
 End Property
 Public Overrides Function ToString() As String
   Return String.Format("({0}, {1})", xPos, yPos)
 End Function

End Structure

 </source>