Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Xabc = X
    Yabc = Y
    If (Button =  1 ) And (X > TreeView1.Left + TreeView1.Width) And (X < ListView1( 0 ).Left) _
      And (Y > ListView1( 0 ).Top) And (Y < ListView1( 0 ).Top + ListView1( 0 ).Height) Then
        Screen.MouseIcon = PictureMIcon.Picture
        Screen.MousePointer = vbCustom 'vbSizeWE
        ResizeWindows = True
        DragStartX = X
...

   If ResizeWindows Then
        TreeView1.Width = TreeWidth + (X - DragStartX)
...
        ListView1( 0 ).Move TreeView1.Left + TreeView1.Width +  30 , ListView1( 0 ).Top, ListWidth - (X - DragStartX), ListView1( 0 ).Height

Public Function NewWindowProc(ByVal hwnd As Long, ByVal msg As Long, ByVal wParam As Long, lParam As WINDOWPOS) As Long
' Size bounds in pixels.
Const MIN_WIDTH =  200 
Const MAX_WIDTH =  500 
Const MIN_HEIGHT =  100 
Const MAX_HEIGHT =  300 

    ' Keep the dimensions in bounds.
    If msg = WM_WINDOWPOSCHANGING Then
        If lParam.cx < MIN_WIDTH Then lParam.cx = MIN_WIDTH
        If lParam.cx > MAX_WIDTH Then lParam.cx = MAX_WIDTH
        If lParam.cy < MIN_HEIGHT Then lParam.cy = MIN_HEIGHT
        If lParam.cy > MAX_HEIGHT Then lParam.cy = MAX_HEIGHT
    End If
    
    ' Continue normal processing. VERY IMPORTANT!
    NewWindowProc = CallWindowProc( _
        OldWindowProc, hwnd, msg, wParam, _
        lParam)
End Function

Private Sub pDrawSplitter()
Dim lhDC As Long
Dim hOldBrush As Long
   lhDC = CreateDCAsNull("DISPLAY", ByVal  0 &, ByVal  0 &, ByVal  0 &)
   hOldBrush = SelectObject(lhDC, m_hBrush)
   PatBlt lhDC, m_tSplitR.Left, m_tSplitR.Top, m_tSplitR.Right - m_tSplitR.Left, m_tSplitR.Bottom - m_tSplitR.Top, PATINVERT  'DSTINVERT
   SelectObject lhDC, hOldBrush
   DeleteDC lhDC
End Sub

   PatBlt lhDC, m_tSplitR.Left, m_tSplitR.Top, m_tSplitR.Right - m_tSplitR.Left, m_tSplitR.Bottom - m_tSplitR.Top, PATINVERT  'DSTINVERT

m_cSplitMain.FullDrag = True

m_cSplitMain.FullDrag = True

Private Sub pDrawSplitter()
Dim lhDC As Long
Dim hOldBrush As Long
Dim crBackColor As Long
    'If IsWinVista Then
        lhDC = GetDC(m_oContainer.hWnd)
        crBackColor = SetBkColor(lhDC, vbWhite)
        hOldBrush = SelectObject(lhDC, m_hBrush)
        If (m_eOrientation = cSPLTOrientationVertical) Then
            PatBlt lhDC, m_oContainer.Left + m_lSplitPos,  0 , m_lSplitSize, m_oContainer.Height, PATINVERT
        Else
            PatBlt lhDC,  0 , m_oContainer.Top + m_lSplitPos, m_oContainer.Width, m_lSplitSize, PATINVERT
        End If
        SelectObject lhDC, hOldBrush
        SetBkColor lhDC, crBackColor
        ReleaseDC m_oContainer, lhDC
    'Else
    '    lhDC = CreateDCAsNull("DISPLAY", ByVal 0&, ByVal 0&, ByVal 0&)
    '    hOldBrush = SelectObject(lhDC, m_hBrush)
    '    PatBlt lhDC, m_tSplitR.Left, m_tSplitR.Top, m_tSplitR.Right - m_tSplitR.Left, m_tSplitR.Bottom - m_tSplitR.Top, PATINVERT
    '    SelectObject lhDC, hOldBrush
    '    DeleteDC lhDC
    'End If
End Sub

Public Sub MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
...
         If Not (m_bFullDrag) Then
...
            '==================================
            'If IsWinVista Then
                wsStyle = GetWindowLong(m_oContainer.hWnd, GWL_STYLE)
                SetWindowLong m_oContainer.hWnd, GWL_STYLE, wsStyle And Not WS_CLIPCHILDREN '.picSplitMain
            'End If
            '=================================
            pDrawSplitter
...

Public Sub MouseUp(Button As Integer, Shift As Integer, x As Single, y As Single)
...
         If Not m_bFullDrag Then
            pDrawSplitter
            '====================
            'If IsWinVista Then
                SetWindowLong m_oContainer.hWnd, GWL_STYLE, wsStyle
            'End If
            '====================
         End If
...

Public Sub MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
...
         '====================================
         SetCursor m_hCursor 'без этого курсор исчезнет в момент нажатия
         '===================================
...

If IsWinVista Then
    OldSplitWindowProc = SetWindowLong(picSplitMain.hwnd, GWL_WNDPROC, _
        AddressOf NewSplitWindowProc)
End If
...
Public OldSplitWindowProc As Long

Public Function NewSplitWindowProc(ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    'для событий picSplitMain
    If (Msg = &H7) Then ' Const WM_SETFOCUS = &H7
        Debug.Print wParam
        If Form1.TreeView1.hwnd = wParam Then
            'Call SendMessage(wParam, &H7, 0&, 0&)
            Form1.TreeView1.SetFocus
        End If
    End If
    NewSplitWindowProc = CallWindowProc( _
        OldSplitWindowProc, hwnd, Msg, wParam, _
        lParam)
End Function

    OldНечтоWindowProc = SetWindowLong(Нечто.hwnd, GWL_WNDPROC, _
        AddressOf NewНечтоWindowProc)
...
Public OldНечтоWindowProc As Long

Public Function NewНечтоWindowProc(ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    'для событий Нечто
    If (Msg = &H215) Then ' Const WM_CAPTURECHANGED = &H215
         To Do что-то
         Exit Sub '???
    EndIf
    NewНечтоWindowProc = CallWindowProc( _
        OldSplitWindowProc, hwnd, Msg, wParam, _
        lParam)
End Function

        SetWindowTheme TreeView1.hwnd, StrPtr("explorer"),  0 
        SetWindowTheme ListView1.hwnd, StrPtr("explorer"),  0 

Public Sub MouseUp(Button As Integer, Shift As Integer, x As Single, y As Single)
...
         If Not m_bFullDrag Then
            pDrawSplitter
            '====================
                 SetWindowLong m_oContainer.hWnd, GWL_STYLE, wsStyle
            '====================
         End If
...

Private Sub picSplitMain_MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
   Hook Me.picSplitMain.hwnd
   m_cSplitMain.MouseDown Button, Shift, x, y
End Sub

Private Sub picSplitLeft_MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
   Hook Me.picSplitLeft.hwnd
   m_cSplitLeft.MouseDown Button, Shift, x, y
End Sub

Set m_splitter = m_cSplitMain

   Set m_splitter = m_cSplitMain
   Set m_splitter2 = m_cSplitLeft

Public m_splitter As cSplitter
Public m_splitter2 As cSplitter

    If uMsg = WM_CAPTURECHANGED Then
          'Debug.Print "WM_CAPTURECHANGED"
          Call Unhook
          If hw = frmSplitTest.picSplitMain.hwnd Then
            m_splitter.MouseUp  0 ,  0 ,  0 ,  0 
          ElseIf hw = frmSplitTest.picSplitLeft.hwnd Then
            m_splitter2.MouseUp  0 ,  0 ,  0 ,  0 
          End If
    Else

Public Function NewSplitWindowProc(ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    'для событий picSplitMain
    If (Msg = &H7) Then ' Const WM_SETFOCUS = &H7
        Debug.Print wParam
        If Form1.TreeView1.hwnd = wParam Then
            'Call SendMessage(wParam, &H7, 0&, 0&)
            Form1.TreeView1.SetFocus
        End If
    End If
    NewSplitWindowProc = CallWindowProc( _
        OldSplitWindowProc, hwnd, Msg, wParam, _
        lParam)
End Function