Form sizing to fill screen dimensions minus taskbar

Question

How do you size your form in vb6 so that form lower border is at top of taskbar

Answer 1

Is there a reason you cannot just maximise the form? That would be my first impression.

If that's not a runner, you could try getting the taskbar height in the following way:

Private Const ABM_GETTASKBARPOS = &H5

Private Type RECT
    Left As Long
    Top As Long
    Right As Long
    Bottom As Long
End Type

Private Type APPBARDATA
    cbSize As Long
    hwnd As Long
    uCallbackMessage As Long
    uEdge As Long
    rc As RECT
    lParam As Long
End Type

Private Declare Function SHAppBarMessage Lib "shell32.dll" (ByVal dwMessage As Long, pData As APPBARDATA) As Long


Function GetTaskBarSize()
    Dim ABD As APPBARDATA

    SHAppBarMessage ABM_GETTASKBARPOS, ABD

    MsgBox "Width:" & ABD.rc.Right - ABD.rc.Left 
    MsgBox " Height:" & ABD.rc.Bottom -    ABD.rc.Top

End Sub

and then setting your form's height to the screen's height less the taskbar's height.

Answer 2

Minus only the taskbar? That might not really be what you want. There can be other windows on the edges of the screen that are meant to "carve out" regions of the desktop. Also, note that sometimes the height of the taskbar is irrelevant, such as when it's docked to the left or right side of the screen.

Galwegian has shown how to get the height of the taskbar, but if you're really looking for the usable area of the desktop, use the SystemParametersInfo function with the spi_GetWorkArea flag instead. It will tell you the area of the desktop excluding all desktop toolbars. MSDN advises that if you're interested in the space available on something other than the primary monitor, you should call GetMonitorInfo instead; it fills a record, and one of the fields is for the monitor's work area.

I'm going to second the idea that you might really just want to maximize your window. If you've already done that, and you want to know how much space you're taking up, then get the current size of your window, and then subtract the dimensions of your window's frame (which get "tucked under the edges" of the desktop when a window is maximized). You can use GetSystemMetrics with the sm_CXFrame and sm_CYFrame flags for that.

Answer 3

I'm going to agree you probably want to maximize your window.

But if you really do want to know the area of the desktop excluding all desktop toolbars (taskbar, Microsoft Office toolbar, etc), here's some VB6 declarations for the SystemParametersInfo call and a sample function that centres forms on the screen, allowing for the toolbars. This is borrowed from 101 tech tips (PDF) from the old Visual Basic Programmers Journal.

Private Const SPI_GETWORKAREA = 48
Private Declare Function SystemParametersInfo& Lib "User32" Alias "SystemParametersInfoA" ( _
ByVal uAction As Long, _
ByVal uParam As Long, lpvParam As Any, _
ByVal fuWinIni As Long)

Private Type RECT
  Left As Long
  Top As Long
  Right As Long
  Bottom As Long
End Type

Public Function CenterForm32 (frm As Form)
  Dim ScreenWidth&, ScreenHeight&, ScreenLeft&, ScreenTop&
  Dim DesktopArea As RECT
  Call SystemParametersInfo (SPI_GETWORKAREA, 0, DesktopArea, 0)

  ScreenHeight = (DesktopArea.Bottom - DesktopArea.Top) * Screen.TwipsPerPixelY
  ScreenWidth = (DesktopArea.Right - DesktopArea.Left) * Screen.TwipsPerPixelX
  ScreenLeft = DesktopArea.Left * Screen.TwipsPerPixelX
  ScreenTop = DesktopArea.Top * Screen.TwipsPerPixelY

  frm.Move (ScreenWidth - frm.Width) \ 2 + ScreenLeft, _
    (ScreenHeight - frm.Height) \ 2 + ScreenTop
End Function