How to use Delegates in VB.Net

'Author : Pramod Kumar Singh
'Purpose : To show HOW Delegates WORKS in VB7
'Applicatio : Console
'Date : 5th Jan 2001
'History :

Module Module1
'Define a Delegate
Delegate Sub CompareFunc(ByVal x As Integer, _
ByVal y As Integer, ByRef b As Boolean)
'Define a Event that will be used in AddHandler

Public Event a As CompareFunc
'Bubble Sort Algorithm which calles Delegates to perform work
Function BubbleSort(ByVal SortHigher As CompareFunc, _
ByVal IntArray() As Integer) As Integer()
Dim I, J, Value, Temp As Integer
Dim b As Boolean
For I = 0 To Ubound(IntArray)
Value = IntArray(I)
For J = I + 1 To UBound(IntArray)
Try
SortHigher.Invoke(IntArray(J), Value, b)
If b = True Then
Temp = IntArray(J)
IntArray(J) = Value
IntArray(I) = Temp
Value = Temp
End If
Catch
'Add error handling here, or just proceed
End Try
Next J
Next I
End Function

'Actual Event handling , called by Delgates
Sub Fire(ByVal x As Integer, ByVal y As Integer, ByRef b As Boolean)
If y > x Then
b = True
Else
b = False
End If
End Sub

'Entry point
Sub Main()
Dim IntArray() As Integer = {12, 1, 96, 56, 70}
Dim iArrayCount As Integer
Dim iCounter As Integer
' Add a delegate Handler
AddHandler a, (AddressOf Fire)
'Define Array for Sorting
iArrayCount = IntArray.Length
Console.WriteLine("Integer array to be sorted")
For iCounter = 0 To iArrayCount - 1
Console.WriteLine(" Value at{0} is {1} ", _
iCounter, IntArray(iCounter))
Next
'Call the method which is going to raise events
BubbleSort(Module1.aEvent, IntArray)
iArrayCount = IntArray.Length
Console.WriteLine("Integer array after Bubble Sort with Delegate")
'Display the Data to user on Console
For iCounter = 0 To iArrayCount - 1
Console.WriteLine(" Value at{0} is {1}", _
iCounter, IntArray(iCounter))
Next

End Sub
End Module