C# WinForms disable DPI scaling

Question

I have a WinForm application which hosts many images. When I put the application on a Win7 machines that has a DPI of 120, it completely ruins the look of the form. Is there a way to disable the scaling for my form?

I am aware that this is something that is not advised and that DPI should be seamless and handled by the OS. But when it comes to a skinned application, the images do not scale well. I do not have the luxury of creating images for all the DPI variations, so please don't suggest that as an answer.

Hans Passant · Accepted Answer · 2016-08-04T12:23:36.550

You'll have bigger problems when you change the AutoScaleMode property. Increasing the DPI also changes the system font size. Necessarily so, font sizes are expressed in points, 1/72 inch. The fonts need to be bigger to get the same point size when the DPI increases and keep the text just as readable when viewed from the same distance.

Since the controls don't get resized anymore, the text on, say, a button no longer fits. One way to battle this is to change the font size on the controls proportionally. Easy if you let all the controls inherit the form font, just changing the form's Font property automatically updates the controls as well. The clear disadvantage is that the user will have a harder time reading the text. This especially gets bad when the DPI goes to 150 dots per inch and beyond, your UI just turns into an unusable postage stamp.

Yes, background images need to get scaled to fit the larger control or form. A pixel in the image now no longer maps one-to-one to a pixel of the monitor. The default Graphics.InterpolationMode value does a fairly decent job of filtering the image. But it depends on the kind of image how well that turns out. A photo almost always scales very well. Finely detailed line art and text does not. Picking the right kind of image goes a long way to avoiding having to create separate ones.

This problem isn't going to go away until monitors start to have the kind of resolution a printer has. We're still a long way from 600 dpi for desktop monitors. Phones will be first.

600 DPI screens are becoming reality. Just look at your phone (ok, not 600 but 480 are here). The future is here. — Hooch, Nov 30 '15 at 07:50

score 10 · Answer 2 · answered Nov 25 '19 at 20:05

10

Create a application manifest file (right-click on project/ add/new item/application file) and uncomment this section:

<application xmlns="urn:schemas-microsoft-com:asm.v3">
  <windowsSettings>
    <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware
  </windowsSettings>
</application>

Creds to this site: https://www.telerik.com/blogs/winforms-scaling-at-large-dpi-settings-is-it-even-possible-

answered Nov 25 '19 at 20:05

Xavier Follet

191
2
6

This worked for me. The form is still to big for my laptop screen but at least it is not now being shrunk and making some controls inaccessible. – tonyb Aug 12 '20 at 07:15

score 9 · Answer 3 · answered Jul 02 '14 at 11:24

9

Adding one line of code before the auto-generated call to InitializeComponent in the Form1-constructor solved it for me:

public partial class Form1 : Form
{
    public Form1()
    {
        // Make the GUI ignore the DPI setting
        Font = new Font(Font.Name, 8.25f * 96f / CreateGraphics().DpiX, Font.Style, Font.Unit, Font.GdiCharSet, Font.GdiVerticalFont);
        InitializeComponent();
    }
}

answered Jul 02 '14 at 11:24

Helper

91
1
1

2

Doesn't work at all on Windows 10 with a 150% scaled 4K monitor – Hexo Oct 07 '16 at 12:42
Combining this with setting AutoScaleMode to None solved the problem for me – Zarat Jan 16 '18 at 10:43
2

doesn't work on windows 10 with 150% or 200% even with `AutoScaleMode = None` – Franck Aug 09 '18 at 12:42
This solved it for me on Windows 10 (1809) 150% scaling – Fredrik C Jun 14 '19 at 08:54
1

Using `actualPixelSize * 100f / CreateGraphics().DpiY` worked for me. This should compensate for any DPI scaling. – Pieter12345 Sep 17 '19 at 23:38
@Pieter12345 - excuse me, what is "actualPixelSize"? Can you explain how to determne this variable? – S.H. Sep 06 '22 at 09:00
@S.H. `actualPixelSize` is the pixel size that you choose a component to be. You essentially undo the current DPI scaling, placing it back at 100%. – Pieter12345 Sep 07 '22 at 12:35

score 3 · Answer 4 · answered Oct 24 '10 at 17:05

3

You can set the AutoScaleMode property of the form to None.

answered Oct 24 '10 at 17:05

Jeff Ogata

56,645
19
114
127

1

Combining this with manually scaling the fonts of the controls (as suggested in another solution here) solved the problem for me. – Zarat Jan 16 '18 at 10:43

C# WinForms disable DPI scaling

4 Answers4

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