David Cannon said:

but I believe (and I may be wrong) that Windows 10 now uses Segoe UI as the default font, and I am suspecting that as of update 1803, that maybe Bahnscrift is now being applied as a default font in some cases

That seems unlikely to me. I mean... if that were the case, then it would be affecting ALL of your controls, not just the grid. There's no reason why the grid would be any different than any other control. The grid is just a class that derives from Control, just like every other control in your application. Whatever is happening in your application is specific to the grid(s). 

Also, if that were the case, then it would be very easy to see. the grid's Font property would be returning Segoe UI or Bahnscrift, not MS Sans Serif. 

What happens if you create a new application and put a grid on a form with some data? Do you get the same results? If so, then that would indicate that there is something going on with your machine that is causing that. If not, it would indicate that there some factor specific to your application. 

BTW... you mentioned you check for "StyleManager.Load". Did you also check for "DisplayLayout.Load"? That one is a little harder to check for, since it's possible that you could be storing the DisplayLayout in a member variable:

var layout = this.ultraGrid1.DisplayLayout;

And then calling layout.Load.

One other thing to check for would be "PresetSerializer". That's another way you could apply a group of settings to the grid without setting a property directly. 

Checking for FontData.Name is tough, because this could be set on a wide variety of Appearance objects. There are literally dozens of them that could be affecting cells. 

One other test you could try is to run this code in a button click and see what it shows in the Output window. That might tell use something about where the font is coming from. 

        private void DisplayFonts(UltraGrid grid)
        {

            Debug.WriteLine(grid.Font.Name, "Grid Font");

            AppearanceData appData = new AppearanceData();
            AppearancePropFlags flags = AppearancePropFlags.FontName;
            grid.DisplayLayout.ResolveLayoutAppearance(ref appData, ref flags, true);
            Debug.WriteLine(appData.FontData.Name, "DisplayLayout font");

            appData = new AppearanceData();
            flags = AppearancePropFlags.FontName;
            grid.DisplayLayout.Rows[0].Cells[0].ResolveAppearance(ref appData, flags);
            Debug.WriteLine(appData.FontData.Name, "Cell Font");
        }

We too saw the Wingdings font issue with the Infragistics UltraWin* controls after applying the Windows 10 April 2018 Update, version 1803.

We had to set a default font for all controls and re-issue new builds for our users.  A big PITA.

Hello David,

Thanks for sharing the above information. As you have verified everything that Mike suggested, we need a sample to investigate further. Please send us a sample with this issue reproduced in it and I will work with my team to see if we can add an easier work around for this Bahnscrift font issue when using Windows 10.1803.

Let me know if you have any questions.

Hi Mike,

I don't mean to sound contradictory, but that is absolutely correct. We do not set any fonts in the controls other than Microsoft San Serif. In the design view, MS Sans Serif is displayed, but at run time, the ultragrid, (And yes, the WHOLE grid, and nothing but the grid) displays using Bahnscrift as illustrated in the images in my initial post.

For clarity of the initial post, I only included the image of the grid, but if I were to display the entire form, you would see that all the other labels, text fields, buttons etc would be using MS Sans Serif as expected. This behavior is limited to the grid. In addition to Bahnscrift, when a grid cell is activated in edit mode, the text is rendered as Wingding (which is what first alerted us to an issue).

I am certain that the Bahnscrift font is not being applied by our code. We actually wrap the Infragistics controls and make use of abstracted base forms to provide consistent behavior across the UI. (Yes, this affects all the grids in our UI, approximately 1800 of them)  I have actually tested the DisplayLayout in debug to see if we are setting the FontData Name name at runtime, and we are not setting any value there. I also looked for references to StyleManager.Load, and there are no references found in the solution. We set the font name at the control level, and never apply any layout configuration beyond that. 

How did I determine the grid is using Bahnscrift? I'm glad you asked. It was actually quite painful. I tried some online font programs where i submitted an image, but wasn't having any luck. So then I painstakingly tested each font (I have 186 on my local workstation) using the same string as the affected grid title "Records Matching Filter Criteria" until I visually found a match. I actually found about a half dozen that were close, but continued to narrow that down until we were certain it was bahnscrift. Then, I updated my registry to point the bahnscrift font to use Arial, and when I restarted and relaunched the form, I found that the grid no longer displayed the wonky font.

Now this is where it gets interesting... I did a little additional digging on Bahnscrift. It turns out that it is a brand new font from Windows that became installed as a system font with update 1803. The only users that are reporting this issue are the ones on Windows 10 Update 1803. My laptop has Windows 10 update 1703, and it is unaffected. It was only with this latest update that we began to have issues. Here is my guess as to what is happening. Because we don't define the font in the grid's display layout, Windows is now applying Bahnscrift as a default font. I know you mentioned that .Net defaults to the ambient font of MS Sans Serif, and I think that is true for Windows 7, but I believe (and I may be wrong) that Windows 10 now uses Segoe UI as the default font, and I am suspecting that as of update 1803, that maybe Bahnscrift is now being applied as a default font in some cases. I attempted to uninstall Bahnscrift, but it is a protected font. Best I could do was create a registry entry for Font Substitute to route to Microsoft Sans Serif anytime Bahnscrift is used. 

Hi David, 

You seem to be saying some contradictory things here. You repeatedly say that you are not using any custom fonts and that everything in your application is using MS Sans Serif, but then you say that that grid is displaying using Bahnscrift.

Are you saying that Bahnscrift is being used to display the grid even though you have not set it to do so anywhere in your application? 

If you don't set a font on anything, then the DotNet framework falls back to the ambient font, which on American English machines is MS Sans Serif. There's nothing in the grid that would change that for any reason. So if your grid is using Bahnscrift then something in your application has to be assigning that font somewhere. 

If you search your code for "Bahnscrift" and don't find it, then there are several other places it could be coming from. If you are loading a layout into the grid, the layout might be setting a font on any one of the grid's Appearance properties. In this case, since the font is only appearing in the active cell, then the obvious guess would be the EditCellAppearance on the Override of either the DisplayLayout or the band. It could also be applied to the ActiveCellAppearance, so I would recommend putting a button on your form as a test and then at run-time, check the font name on all of these appearances: 

            Debug.WriteLine(this.ultraGrid1.DisplayLayout.Override.EditCellAppearance.FontData.Name);
            Debug.WriteLine(this.ultraGrid1.DisplayLayout.Bands[0].Override.EditCellAppearance.FontData.Name);
            Debug.WriteLine(this.ultraGrid1.DisplayLayout.Override.ActiveCellAppearance.FontData.Name);
            Debug.WriteLine(this.ultraGrid1.DisplayLayout.Bands[0].Override.ActiveCellAppearance.FontData.Name);

If that doesn't turn up anything useful, then another possibility is that one of these settings is being affected by AppStylist. Check your code for a call to the "StyleManager.Load" method to see if you are loading a style library. If so, then this could be affecting the font without actually setting any of the properties on the grid. 

BTW... How did you determine that the grid is display using Bahnscrift? Do you mean the WHOLE grid? Or just the active cell in edit mode?