Visual Basic API FAQs

[EJ12N]

Add Horizontal Scroll bar to Listboxes

'PUT IN MODULE...
Public Const LB_SETHORIZONTALEXTENT = &H194
Public Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
 
Public Sub HorizontalSbar(List1 As ListBox)
 
Dim lngReturn As Long
Dim lngExtent As Long
 
lngExtent = 2 * (List1.Width / Screen.TwipsPerPixelX)   'Set the Horizontal Bar to 2 times its Width
 
lngReturn = SendMessage(List1.hwnd, LB_SETHORIZONTALEXTENT, lngExtent, 0&)
End Sub
 
'USAGE:
'Call HorizontalSbar(LISTBOX_NAME_HERE)

Move Form With No Border

Private Declare Function ReleaseCapture Lib "user32" () As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
 
Public Sub DragForm(frm As Form)
    ReleaseCapture
    Call SendMessage(frm.hwnd, &HA1, 2, 0&)
End Sub
 
'USAGE:
'Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X 'As Single, Y As Single)
'DragForm Me
'End Sub

Transparent Form

Option Explicit
Private Declare Function CreateRectRgn Lib _
    "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, _
    ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CombineRgn Lib _
    "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, _
    ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
Private Declare Function SetWindowRgn Lib _
    "user32" (ByVal hWnd As Long, ByVal hRgn As Long, _
    ByVal bRedraw As Boolean) As Long
Private Declare Function DeleteObject Lib _
    "gdi32" (ByVal hObject As Long) As Long
 
' Constants used by the CombineRgn function
Private Const RGN_AND = 1
Private Const RGN_OR = 2
Private Const RGN_XOR = 3
Private Const RGN_DIFF = 4
Private Const RGN_COPY = 5
 
Private Sub Form_Activate()
    Dim rgnForm As Long, rgnCombined As Long
    Dim rgnControl As Long, x As Long
    Dim formWidth As Single, formHeight As Single
    Dim borderWidth As Single, titleHeight As Single
    Dim ctlLeft As Single, ctlTop As Single
    Dim ctlWidth As Single, ctlHeight As Single
    Dim ctl As Control
 
    ' Calculate the form area
    borderWidth = (Me.Width - Me.ScaleWidth) / 2
    titleHeight = Me.Height - Me.ScaleHeight - borderWidth
    ' Convert to Pixels
    borderWidth = ScaleX(borderWidth, vbTwips, vbPixels)
    titleHeight = ScaleY(titleHeight, vbTwips, vbPixels)
    formWidth = ScaleX(Me.Width, vbTwips, vbPixels)
    formHeight = ScaleY(Me.Height, vbTwips, vbPixels)
    
    ' Create a region for the whole form
    rgnForm = CreateRectRgn(0, 0, formWidth, formHeight)
    
    rgnCombined = CreateRectRgn(0, 0, 0, 0)
    ' Make the graphical area transparent by combining the two regions
    x = CombineRgn(rgnCombined, rgnForm, rgnForm, RGN_DIFF)
 
    ' Make the controls visible
    For Each ctl In Controls
        ' Make the regions of controls whose container is the form visible
        If TypeOf ctl.Container Is Form Then
            ctlLeft = ScaleX(ctl.Left, vbTwips, vbPixels) + borderWidth
            ctlTop = ScaleX(ctl.Top, vbTwips, vbPixels) + titleHeight
            ctlWidth = ScaleX(ctl.Width, vbTwips, vbPixels) + ctlLeft
            ctlHeight = ScaleX(ctl.Height, vbTwips, vbPixels) + ctlTop
            rgnControl = CreateRectRgn(ctlLeft, ctlTop, ctlWidth, ctlHeight)
            x = CombineRgn(rgnCombined, rgnCombined, rgnControl, RGN_OR)
        End If
    Next ctl
    
 
    ' Set the clipping area of the window using the resulting region
    SetWindowRgn hWnd, rgnCombined, True
    ' Tidy up
    x = DeleteObject(rgnCombined)
    x = DeleteObject(rgnControl)
    x = DeleteObject(rgnForm)
End Sub

:-)