Public Class MyComboBox
		Inherits ComboBox
		Private _Locked As Boolean
		Public Property Locked As Boolean
			Get
				Return _Locked
			End Get
			Set (Value As Boolean)
				_Locked = Value
				If Value Then Me.BackColor = Color.AliceBlue 
				If Not Value Then Me.BackColor = Color.White
			End Set
		End Property
		Private Const WM_PAINT As Int32 = &HF
		Private Const WM_KEYDOWN As Int32 = &H100
		Private Const WM_LBUTTONDOWN As Int32 = &H201
		Private Const WM_ACTIVATE As Int32 = &H6
		Private Const WM_LBUTTONDBLCLK As Int32 = &H203
		Protected Overrides Sub WndProc(ByRef m As Message)
			If Locked AndAlso ( _ 
								m.msg = WM_KEYDOWN OrElse _
							  	m.msg = WM_LBUTTONDOWN OrElse _ 
							  	m.msg = WM_LBUTTONDBLCLK OrElse _
							  	m.msg = WM_ACTIVATE) Then
                          Return
			End If
			MyBase.WndProc(m)
		End Sub
		Public Overrides Function PreProcessMessage(ByRef m As Message) As Boolean
			If Locked AndAlso Not m.Msg = WM_PAINT Then Return True		
		End Function
End Class