Public Class PushButton
  Implements IUIControl

  Dim m_rcRect As Drawing.Rectangle

  'Interface implementation
  '........................
  Public Sub Paint() Implements IUIControl.Paint
    ' Paint the control
  End Sub

  Public Function IsPtInControl(ByVal Pt As Drawing.Point) _
  As Boolean Implements IUIControl.IsPtInControl
    IsPtInControl = Pt.Equals(ControlRect())
  End Function

  Public Property ControlRect() As Drawing.Rectangle _
  Implements IUIControl.ControlRect
    Get
      ControlRect = m_rcRect
    End Get
    Set(ByVal Value As Drawing.Rectangle)
      m_rcRect = Value
    End Set
  End Property

  Public Sub ControlPressed() Implements IUIControl.ControlPressed
    RaiseEvent ControlHit()
  End Sub

  Public Event ControlHit() Implements IUIControl.ControlHit

  'Other class specific code
  '.........................

End Class

Public Class RadioButton
  Implements IUIControl

  Dim m_rcRect As Drawing.Rectangle

  'Interface implementation
  '........................
  Public Sub Paint() Implements IUIControl.Paint
    ' Paint the control
  End Sub

  Public Function IsPtInControl(ByVal Pt As Drawing.Point) _
  As Boolean Implements IUIControl.IsPtInControl
    IsPtInControl = Pt.Equals(ControlRect())
  End Function

  Public Property ControlRect() As Drawing.Rectangle _
  Implements IUIControl.ControlRect
    Get
      ControlRect = m_rcRect
    End Get
    Set(ByVal Value As Drawing.Rectangle)
      m_rcRect = Value
    End Set
  End Property

  Public Sub ControlPressed() Implements IUIControl.ControlPressed
    RaiseEvent ControlHit()
  End Sub

  Public Event ControlHit() Implements IUIControl.ControlHit

  'Other class specific code
  '.........................

End Class