How can I find the width of the parent window in MS-Access

Question

I'm trying to force an MS-Access form to take a certain position relative to the right edge of the main window (actually I want to center it, but I can see also wanting to dock it to one side or another). I can reposition the form this with Me.Move, e.g.,

    Me.Move newWindowLeft, newWindowTop, newWidth, newHeight

However, how can I find out how wide the parent window is?

Answer 1

You can use a windows API:

(UPDATED to return twips)

Type Rect
    x1 As Long
    y1 As Long
    x2 As Long
    y2 As Long
End Type

Declare Function GetClientRect Lib "user32" (ByVal hwnd As Long, lpRect As Rect) As Long

Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long

Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long

Declare Function GetDeviceCaps Lib "gdi32" (ByVal hdc As Long, ByVal nIndex As Long) As Long

Const LOGPIXELSX = 88
Const LOGPIXELSY = 90
Const DIRECTION_VERTICAL = 1
Const DIRECTION_HORIZONTAL = 0

Public Function GetMainWindowSize()

    Dim MDIRect As Rect
    Dim lWidthPixels As Long
    Dim lWidthTwips As Long

    ' Get the screen coordinates and window size of the MDIClient area'
    GetClientRect Application.hWndAccessApp, MDIRect

    lWidthPixels = MDIRect.x2 - MDIRect.x1
    lWidthTwips = PixelsToTwips(lWidthPixels, DIRECTION_HORIZONTAL)

    MsgBox "Width (Pixels) = " & lWidthPixels & "  Width (Twips) = " & lWidthTwips

End Function


Function PixelsToTwips(lPixels As Long, lDirection As Long) As Long

    Dim lDeviceHandle As Long
    Dim lPixelsPerInch As Long

    lDeviceHandle = GetDC(0)

    If lDirection = DIRECTION_HORIZONTAL Then
        lPixelsPerInch = GetDeviceCaps(lDeviceHandle, LOGPIXELSX)
    Else

        lPixelsPerInch = GetDeviceCaps(lDeviceHandle, LOGPIXELSY)
    End If

    lDeviceHandle = ReleaseDC(0, lDeviceHandle)

    PixelsToTwips = lPixels * 1440 / lPixelsPerInch

End Function

Answer 2

Not sure what version of Access you are using, but in Access 2003, there does not appear to be a way to directly get this information.

Here's a hack:

DoCmd.Maximize

w = Forms("yourForm").WindowWidth
h = Forms("yourForm").WindowHeight

This will maximize the current window, let's assume that it's your form. You can then measure the form to get the size of the parent window's display area, then un-maximize, and move the form based on the size of the parent window that you now know.

If there is a way to turn off ScreenUpdating in Access, you can do this before the maximize and measure code, then turn it back on, and it won't take any noticeable amount of time as far as the user is concerned.

EDIT: Even without hiding the maximize command from the user, the whole maximize and move operation happens more quickly than the user can see.

It's an ugly hack, but it does work.