Make all controls inside a Groupbox or Panel unusable without disabling them

Question

Hello !
I'm using Vb.net 2013 , NET 4.0.
I'm trying to make all the controls inside a Groupbox ( or Panel) , unusable by users if a condition is true.
This is the code that I'm using :
Class NW
Inherits NativeWindow
Public Sub New(hwnd As IntPtr)
AssignHandle(hwnd)
End Sub
Const WM_NCHITTEST As Integer = &H84
Protected Overrides Sub WndProc(ByRef m As Message)
If m.Msg = WM_NCHITTEST Then
Return
End If
MyBase.WndProc(m)
End Sub
End Class
Dim nwss As List(Of NW) = Nothing
Public Sub block_area(flag As Boolean)
If flag = True AndAlso IsNothing(nwss) Then
nwss = New List(Of NW)()
For Each c As Control In GroupBox1.Controls
nwss.Add(New NW(c.Handle))
Next
Else
If flag = False And (Not IsNothing(nwss)) Then
For Each nw As Object In nwss
nw.ReleaseHandle()
Next
nwss = Nothing
End If
End If
End Sub
The problem is that this code works for all controls , except the TextBox and DateTimePicker . These 2 controls remain always clickable and editable so usable by users.
 What can I do ?
Thank you !

Answer 1

Ok , friend , if you don't like this question , you can close it anytime. Next time when I need to make a question , I will be careful to do more hard questions like : " What will be the final result of a=1  a=a+1" . This is pure VB.net ,
I think.
I'm sorry if it upsets you that your code will not work as intended. Everyone here is just trying to help you understand that there is no good solution to your problem from a managed code perspective in Windows Forms. The best answers are to use a different
presentation system or to spin your own custom control at the Win32 level (or buy one from someone else who has already done all of that work). The next bester answer is to fudge it with an image that you capture and update as appropriate.
Reed Kimble - "When you do things right, people won't be sure you've done anything at all"
ok , can you only give me a simple answer : What is the WM code that has to do with pressing keys from keyboards in a control ? I try to modify my code if you help me with this. Thank you !
Hello Friend Here is my sample - very elementary, please make more good:
Public Class clsControl
Inherits Control
Public actualControl As Control
Private Property hiddenLock As Boolean = False
Public Property lock As Boolean
Get
Return hiddenLock
End Get
Set(value As Boolean)
If value Then
Dim _bmp As New Bitmap(actualControl.Width, actualControl.Height)
actualControl.DrawToBitmap(_bmp, actualControl.ClientRectangle)
actualControl.Enabled = False
actualControl.Visible = False Me.BackgroundImage = _bmp
Me.Controls.Remove(actualControl)
Else
actualControl.Enabled = True
actualControl.Visible = True
Me.Controls.Add(actualControl)
Me.BackgroundImage = Nothing
End If
hiddenLock = value
End Set
End Property
Public Sub New(ByRef _control As Control)
actualControl = _control
Me.Controls.Add(actualControl)
actualControl.Location = New Point(0, 0)
actualControl.Visible = True
End Sub
End Class
'FORM1 CODE
Private _c As clsControl
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim _txt As New TextBox
_txt.Size = New Size(100, 20)
_txt.Visible = True
_c = New clsControl(CType(_txt, Control))
Me.Controls.Add(_c)
_c.Size = _txt.Size
_c.Visible = True
End Sub
Private Sub Form1_Click(sender As Object, e As EventArgs) Handles Me.Click
_c.lock = Not _c.lock
End Sub
Enjoy friend I spent time to make it work.