Simulate Full Screen or Dim the Background

[NDayave]

In looking into transparent forms, I came across a rather simple solution to the "Run in Fullscreen" feature severely lacking in Access, adapted from the MSDN article at Modal Dialogs with Transparent Backgrounds (MSDN)

If you simply want a solid colour to fill the whole screen, make a form with that colour Detail and set:
- Scroolbars = Neither
- Record Selectors = No
- Navigation Buttons = No
- Dividing Lines = No
- Auto Resize = No
- Auto Centre = Yes
- Pop up = Yes
- Modal = No
- Border Style = None

If you want a picture, you'll need to make different size forms to fill different resolutions and open the relevant form.

In the form's VBA enter

Private Sub Form_Resize()
    Me.Painting = False
    DoCmd.Maximize
    Me.Painting = True
End Sub

On the form that opens with the database, On Load enter:

    With DoCmd
        .Echo False
        .OpenForm <FormName>
        .Echo True
    End With

and On Close Enter:

If (CurrentProject.AllForms(<Form Name>).IsLoaded) Then
        DoCmd.Close acForm, <Form Name>
End If

This will fill the entire background of the screen and provided you set your other forms to Pop Up as well it will stay that way.

If you want to make it transparent for a dimming effect for errors or logins etc. add a module:

Private Declare Function GetWindowLong Lib "User32" Alias "GetWindowLongA" _
  (ByVal hWnd As Long, _
   ByVal nIndex As Long) As Long
 
Private Declare Function SetWindowLong Lib "User32" Alias "SetWindowLongA" _
  (ByVal hWnd As Long, _
   ByVal nIndex As Long, _
   ByVal dwNewLong As Long) As Long
 
Private Declare Function SetLayeredWindowAttributes Lib "User32" _
  (ByVal hWnd As Long, _
   ByVal crKey As Long, _
   ByVal bAlpha As Byte, _
   ByVal dwFlags As Long) As Long
 
Private Const LWA_ALPHA     As Long = &H2
Private Const GWL_EXSTYLE   As Long = -20
Private Const WS_EX_LAYERED As Long = &H80000
 
Public Sub SetFormOpacity(frm As Form, sngOpacity As Single)
    Dim lngStyle As Long
 
    ' get the current window style, then set transparency
    lngStyle = GetWindowLong(frm.hWnd, GWL_EXSTYLE)
    SetWindowLong frm.hWnd, GWL_EXSTYLE, lngStyle Or WS_EX_LAYERED
    SetLayeredWindowAttributes frm.hWnd, 0, (sngOpacity * 255), LWA_ALPHA
End Sub

and change the resize sub on the background form to:

Private Sub Form_Resize()
    Me.Painting = False
    DoCmd.Maximize
    SetFormOpacity Me, 0.7
    Me.Painting = True
End Sub

When combined with several dimming 'stages', forms can effectively fade in and out when opened and closed as well as becoming slightly transparent when they lose focus.
Note: To achieve a smooth fade, you need to remove all the Me.Painting = attributes.

When the forms have no borders, this can create a very nice floating form effect.