Delegate - Sample -1

'// Assumes  Form-1 shows a list of records and Form2 to create a new record. The purpose of this delegate is to update the list view in Form-1 after saving the record.

FORM-1
Public Class Form1

    Private Sub AddOrUpdateRecordallbackFn(ByVal xRec As AuctionInword)
    //Arg - 'AuctionInword' user defined type
    //METHOD IMPLIMENTATION
    End Sub

   Private Sub Button1_Click()
       '// CALL FORM 2
      Dim xfm As New Form2
      '// Point the function
       xfm.AddOrUpdateAICallBack = AddressOf AddOrUpdateRecordallbackFn
       xfm.Show()
     End Sub

End Class


FORM-2
Public Class Form2
    '//Delegate to Form1 function AddOrUpdateRecordallbackFn
    Public Delegate Sub AddOrUpdateRecord(ByVal xRecord As AuctionInword)   
   
    '//variable to point the function
    Public AddOrUpdateAICallBack As AddOrUpdateRecord

Private Sub SaveRecord()
        //Save record implementation
    Dim _CurrentRecord = New <<User Type>> '//To store new record
    -----------------------
    -----------------------
       
    //After Saving, call the Form1 function 'AddOrUpdateRecordallbackFn' using delegate
    If AddOrUpdateAICallBack IsNot Nothing Then AddOrUpdateAICallBack(_CurrentRecord)
End Sub

End Class