[RESOLVED] How to move Form using Title bar without interrupting Processing

[jmsrickland]

I'm working on a real-time application that accepts incoming sound data and plays it back async. This app is in a constant loop reading in the sound data and playing it back using Winsock to receive the data from the server. The problem is if a user mouse down on the title bar and moves the Form the playback is interrupted until user releases the mouse. After user releases the mouse the playback continues but it is now out of sync with the sending of the sound data.

I think that if I subclass the app and capture the mouse down on the title bar I can still allow the user to move his Form without interrupting the playback and getting out of sync.

Here is my subclassing code. All I need are the steps to allow Form movement and not interrupt processing

Form Code

  '
  '
Private Sub cmdStartSubclassing_Click()
 MainOldWindPoc = SetWindowLong(Me.hwnd, GWL_WNDPROC, AddressOf MainWndProc)
End Sub

Private Sub cmdStopSubclassing_Click()
 SetWindowLong Me.hwnd, GWL_WNDPROC, MainOldWindPoc
End Sub
  '
  '

Module Code

Option Explicit

Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" _
 (ByVal hwnd As Long, _
  ByVal nIndex As Long, _
  ByVal dwNewLong As Long) As Long

Public Const WM_SYSCOMMAND As Long = &H112

Public MainOldWindPoc As Long

Public defWndProc As Long

Public Const GWL_WNDPROC& = (-4)

Public Function MainWndProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
 Dim handled As Long
 
 handled = False
    
 Select Case uMsg
   Case WM_SYSCOMMAND
     '
     ' Don't know what to do here
     '
     handled = False
 End Select
    
 If Not handled Then
   MainWndProc = CallWindowProc(MainOldWindPoc, hwnd, uMsg, wParam, lParam)
 End If
End Function

[Zvoni]

I'd rather put the processing code into an activex-dll, since that one gets its own thread from windows

[dilettante]

I'd rather put the processing code into an activex-dll, since that one gets its own thread from windows

DLLs run in-process unless you use them with a proxy (not too practical in VB6). So no, they do not "get a thread" at all but run on the calling thread.

An ActiveX EXE runs out of process, perhaps that's what you were trying to say. These are easy to create using VB6 but to make use of them for independent worker threads takes some finessing.

[Zvoni]

Dilettante, whooops! You're right, of course.
Sorry for the confusion.

[Max187Boucher]

Use Timer(s) instead of Loop(s), put a very small interval.

[jmsrickland]

@Max

I'm using your second EXE suggestion

http://www.vbforums.com/showthread.p...&is_resolved=2