How to make a Form non-movable at Runtime?

Hello to all Forum Members;

Currently I'm working on a project in which under certain circumstances, I need to make the Form unmovable. I know we have the "Moveable" form property but unfortunately that's not available at Runtime. So, I was thinking of doing it in one way or the other. I tried following way of doing it which is a very raw mode and that's why I'm here in need of your expert help.

I added a timer control with Intervel = 20. When I need to lock the form position and want to make it Non moveable then firstly I store the Form's current Left and Top to two module level variables and then enable the timer. On Timer event, I check form's current Top and Left positions with the previously stored one and if different then I restore the previous values emulating the Form as non-movable.

Though it works and serves the purpose, there are two major issues involved in it:

[1] When attempting to move the form in (so called) Locked state, it flickers a lot.
[2] Though the timer is running, I still can move the form from somewhat quickly which is not the proper emulation of "Moveable = False" property.

So, I was thinking of some other way of doing it than this raw method of using VB timer. Can you please suggest me any? Do I need to go for Subclassing? Please guide me how can I achieve the desired effect of "Moveable = False" property at runtime.

Waiting for your valuable reply ...

Regards,

Ruturaaj.

It is doable with subclassing, but there can be a way to do it without subclassing.

If you need to have it always unmovable (e.g. when you change it to be unmovable, it will not be movable again until it is unloaded then reloaded), you can remove the Move item from it's system menu.

Code:

---

Option Explicit

Private Declare Function GetSystemMenu Lib "user32" (ByVal hwnd As Long, ByVal bRevert As Long) As Long
Private Declare Function DrawMenuBar Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function RemoveMenu Lib "user32" (ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long
Const MF_BYPOSITION = &H400&
Const MF_REMOVE = &H1000&

Private Sub Form_Load()
    Dim hSysMenu As Long, nCnt As Long
    ' Get handle to our form's system menu
    ' (Restore, Maximize, Move, close etc.)
    hSysMenu = GetSystemMenu(Me.hwnd, False)

    If hSysMenu Then
        'We found the system menu, so remove the Move item, which is in position 1
        RemoveMenu hSysMenu, 1, MF_BYPOSITION Or MF_REMOVE
        DrawMenuBar Me.hwnd    'Refreshes the System Menu
    End If
End Sub

---

It'll keep all other menu items (Restore, Minimize, Maximize, Close), so the appearance of the form will be unchanged, but you will not be able to move it by the caption bar anymore.

If it needs to be a toggle (e.g. a click makes it unmovable, then another makes it movable again), you likely will have to do subclassing. You can get an idea for what you have to do on this page:
http://www.insteptech.com/techLibrar...tm#Win_No_Move
Ignoring the references to a subclassing control, the code they show is basically what you would have to do (but you'd have to include a Case Else that passes the message to the normal window message handler for the form).

Removing Menu from Control menus is really a new idea to me! Thanks for sharing it. But I need to have an option to toggle this functionality, so better I go for Sub classing. I feel ...

Global Const WM_SYSCOMMAND = &H112
Global Const SC_SIZE = &HF000&
Global Const SC_MOVE = &HF010&

Will make it all for me if I catch them correctly.

Hello,

First of all, I want tho thank ChaosTheEternal
I learnt something interesting.

to Rutu :

Try this (adapted from chaosTheEternal's code ) :

Code:

---

Option Explicit

Private Declare Function GetSystemMenu Lib "user32" (ByVal hwnd As Long, ByVal bRevert As Long) As Long
Private Declare Function DrawMenuBar Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function RemoveMenu Lib "user32" (ByVal hMenu As Long, ByVal nPosition As Long, ByVal wFlags As Long) As Long
Const MF_BYPOSITION = &H400&
Const MF_REMOVE = &H1000&

Private Sub Command1_Click()
  Dim hSysMenu As Long, nCnt As Long
    hSysMenu = GetSystemMenu(Me.hwnd, False)
    If hSysMenu Then
        RemoveMenu hSysMenu, 1, MF_BYPOSITION Or MF_REMOVE
        DrawMenuBar Me.hwnd
    End If
End Sub

Private Sub Command2_Click()
  Dim oux As Integer, ouy As Integer
  oux = Me.Left
  ouy = Me.Top
  Unload Me
  Form1.Move oux, ouy
  Me.Show
End Sub

Private Sub Form_Activate()
  Command1.Caption = "make unmoveable"
  Command2.Caption = "make moveable"
End Sub

---

WOW! Thanks Moa; it works like charm! Gr8! Thanks so much and really many thanks to ChaosTheEternal for sharing this innovative method!