[RESOLVED] Automatic Resizing of all Controls Depending on Screen Resolution

[Hassan Basri]

Hello everybody, I have a form with lots of controls. This form can be used on several user machines each with their own screen résolutions. Instead of manually adding code in the Resize event for each individual control I decided instead to go for 2 procedures. A SaveSizes in the Form Load event and a ResizeControls in the Resize event. This works on about half of screen résolutions I tested. Several controls get resized wrong in the other half of screen résolutions (bigger sizes). Please see my code below if anybody has a suggestion on improving it or a better way of doing this. Thank you.

Declarations

Private Type ControlPositionType
    Left As Single
    Top As Single
    Width As Single
    Height As Single
    FontSize As Single
End Type

Private m_ControlPositions() As ControlPositionType
Private m_FormWid As Single
Private m_FormHgt As Single

Save Sizes called in the Form Load

Private Sub SaveSizes()
Dim i As Integer
Dim ctl As Control

    ' Save the controls' positions and sizes.
    ReDim m_ControlPositions(1 To Controls.Count)
    i = 1
    For Each ctl In Controls
        With m_ControlPositions(i)
            If TypeOf ctl Is Line Then
                .Left = ctl.X1
                .Top = ctl.Y1
                .Width = ctl.X2 - ctl.X1
                .Height = ctl.Y2 - ctl.Y1
            Else
                .Left = ctl.Left
                .Top = ctl.Top
                .Width = ctl.Width
                .Height = ctl.Height
                On Error Resume Next
                .FontSize = ctl.Font.Size
                On Error GoTo 0
            End If
        End With
        i = i + 1
    Next ctl

    ' Save the form's size.
    m_FormWid = ScaleWidth
    m_FormHgt = ScaleHeight
End Sub

ResizeControls called in the Resize event

Private Sub ResizeControls()
Dim i As Integer
Dim ctl As Control
Dim x_scale As Single
Dim y_scale As Single

    ' Don't bother if we are minimized.
    If WindowState = vbMinimized Then Exit Sub

    ' Get the form's current scale factors.
    x_scale = ScaleWidth / m_FormWid
    y_scale = ScaleHeight / m_FormHgt

    ' Position the controls.
    i = 1
    For Each ctl In Controls
        With m_ControlPositions(i)
            If TypeOf ctl Is Line Then
                ctl.X1 = x_scale * .Left
                ctl.Y1 = y_scale * .Top
                ctl.X2 = ctl.X1 + x_scale * .Width
                ctl.Y2 = ctl.Y1 + y_scale * .Height
            Else
                If ctl.Name <> "picClose" Then
                ctl.Left = x_scale * .Left
                ctl.Top = y_scale * .Top
                ctl.Width = x_scale * .Width
                If Not (TypeOf ctl Is ComboBox) Then
                    ' Cannot change height of ComboBoxes.
                    ctl.Height = y_scale * .Height
                End If
                On Error Resume Next
                ctl.Font.Size = y_scale * .FontSize * 0.75
                End If
                On Error GoTo 0
            End If
        End With
        i = i + 1
    Next ctl
End Sub

[dilettante]

Sizing and positioning is one thing, coping with High DPI is another.

In any case your approach is doomed to failure. Trying to "magnify" your Forms is the wrong way to go. Font sizing alone will doom you, since fonts are not pixel-scalable.

You have gone down the wrong path.

[Elroy]

Hi Hassan,

I didn't study your code, but I did read your paragraph. You said "Screen Resolution" but is this truly what you're interested in? There are three related, but very different concepts: 1) screen resolution, 2) dots-per-inch (DPI), and 3) virtual scaling.

As far as I know, the last of those (virtual scaling) only work well on Windows 10.

Regarding screen resolutions, I'm not entirely sure why you'd be interested in that. There's also a fourth concept: the physical size of the monitor.

If screen resolution is less (say 1280 x 960, as compared to 1920 x 1080), what is it you'd like to do? Make your form and controls bigger or smaller? That's very unclear to me. If someone changes their screen resolution, I'd tend to not concern myself with it from my program.

Now, if you're talking about someone changing DPI, LaVolpe has put together an extensive tutorial on this. And be forewarned. It's not a trivial matter.

Personally, for me, if my users want to make things larger, I tell them to get Windows 10, and use its virtualization.



Microsoft has worked hard to make fonts, pictures, and everything scale with a minumum of fuzz/artifact. I'm quite happy with it. And this completely obviates me having to concern myself with it at all.

Good Luck,
Elroy

[Hassan Basri]

Thanks guys, my form is always maximized. So the controls have to be repositioned and resized for different screen resolutions. After some testing I realized that my resizing / repositioning code works correctly. It was my FitTextToLabel function that Elroy was so kind to provide that wasn't working correctly when the screen width was much longer then height. I modified the code to include a check on TextHeight to fix the issue. I will update the thread with the updated function. Thanks again for your comments.