Thanks for looking at this Sahaja. The label and text box controls do not display the same behavior. All of the controls, including the ultra grid, have the font name set to Microsoft Sans Serif. But only the grid is displaying a different font at run time. I narrowed down that the font being displayed in the grid is Bahnscrift. Then, when a cell is selected, the highlighted text is wingdings. I would note that we do not use any custom fonts in our application, we just use the fonts that are included with Windows.

I did notice that the grid control also contains a "Display Layout" property that contains nodes for 'Appearance', each of which contains their own font settings. These font settings were not set by default, so I updated them to use Microsoft Sans Serif in 8 pt, but it still displayed the wayward Bahnscrift and wingdings at run time. 

I found I am able to work around the issue by clearing the Bahnscrift font value in the registry and creating a font substitute that maps Bahnscrift to Microsoft Sans Serif. But I don't feel this is the correct approach to resolving the issue, I would rather fix the software issue instead of hacking the registry.

I will look at getting a code sample to you, it will take me a bit to get a small sample that reproduces the same issue.

The fact that the grid has an additional property (DisplayLayout) that allows you to set the font isn't really relevant to the issue. Or, at least, if it is, I don't see how it could be. The way the appearance resolution works is exactly what you described - if a cell (or any other object in the grid) resolves all of the applicable appearances (like CellAppearance, RowAppearance, etc.) and finds that none of them have set a font, it falls back to the grid control's Font. So in that sense, if you have set no Font name on any applicable appearance, the grid is no different than any other control - it's using the Control's font. The grid doesn't go around the Control.Font and try to get some default font from the system or anything like that. So it's very odd that the grid is the only control in your application that is affected. 

Did you try testing this in a new application? I'd be very curious to see if you can reproduce the same problem in a new application, because that would definitively eliminate the possibility that anything is being set in your app that is affecting the font. 

One other thing you could try is to set the TextRenderingMode and see if that makes any difference. Because one thing that the grid does differently than other controls by default is that it uses GDIPlus instead of GDI text rendering.

Hi Mike,

First of all, I want to say thanks for all your time, input and patience. I know this has been a very weird issue. I did try to create a simple windows form with a grid and could not reproduce the issue. I did attempt to recreate some of the framework around the windows forms that we use in our UI, but I wasn't able to recreate the issue that way either. Our UI can be an over-complicated mess spanning multiple layers of abstraction through hundreds of thousands of lines of code. 

What I did find today is that we do treat the grid a little differently when initializing the control. Let me see if I can explain. First of all, we use an approach called control 'specification' which essentially is a properties wrapper. This goes back to the days when we provided a tool to the client to allow them to customize their forms. That became a maintenance nightmare, so we stopped doing that, however, the specifications live on. We design the form visually, the specification is a property we set that contains behaviors and properties such as stored procedure names, data field mappings and required behavior. We load the form at run time with a reference to the spec. When we configure the control in the initialization method, we grab information from the supplied specification to set the look and feel of the form. 

In the base ControlConfigurator class, we set some font behavior from the specification, including, bold, italic, underline, font size and font name. But there is a conditional statement right before hand that says "If the type is not UltraGrid" do this. So essentially, we skip that configuration step for grids. 

So I applied a subset of that code being skipped to my configuration function for the UltraGrid configuration.

Dim fontSize As Single = Font.Size
If mSpecification.FontSize > 0.0 Then fontSize = CType(mSpecification.FontSize, Single)
Dim fontOfControl As Font = New Font(mSpecification.FontName, fontSize)
Font = fontOfControl

When I step through that code in debug, the grid's Font property shows that the the Font is set to Microsoft Sans Serif, 8.25 as does the instantiated font from the specification. However, there are some differences in the Font's sub properties, namely system font name and original font name:

I don't understand why this behaves differently and what that really means, but I know that if I do not call this code block when I initialize the grid, the native control's Font is used and does the weird rendering thing with Bahnscrift and wingdings. When I do call this code, I initialize a new font using the supplied specification to explicitly apply it to the Grid's Font property, then it renders as expected. This was never an issue until we applied Windows 10 update 1803.

Fortunately, because we wrap everything into abstracted layers, I can just apply this code in our base grid class and it applies to all of our grids and the problem appears resolved. It is just strange to me because before the windows update, it would implicitly apply the correct font, but now we have to explicitly define the font for the grid. And for whatever reason, the other controls are not affected by this. I stepped over the block of code that applies the font from the specification to the other controls, and they rendered the same as they would with the specification.

Hm. Well, if you are happy with that workaround, then that's good. But I agree with you, it doesn't really explain what's happening here. I mean... basically what you are doing here is explicitly setting the grid's Font property to something other than the default - even though you are using MS Sans Serif, it appears to be some other version of MS Sans Serif, perhaps embedded in your application, rather than the system font.

So it makes sense why this would fix the issue, since you are specifying another font, but it doesn't really explain why the issue occurring in the first place. I wonder if it's related to the fact that this font you are using, whatever it is and wherever it's coming from, has the same name as an existing system font and so the DotNet Framework is somehow getting confused. 

You say that this code was basically running and being applied to every control but the grid. I'd be curious to know what happens if you exclude some other control, like the Label or TextBox control. Do those controls then have the same problem the grid was having?

When I step over the configuration block, it doesn't affect how other controls are configured. The other controls do not have the same problem as the grid. That is very curious to me because I would have expected them to display the wrong font like the grid did. I even looked at the lower level properties of the Font and saw that the System Font Name was configured in the same way the grid's font was before I overwrote it with the specification properties in the configuration code. So I am baffled by the whole thing.

¯\_(ツ)_/¯

If you have a morbid curiosity about it, I can possibly see about setting up a web meeting to demonstrate it, but I'm sure you are as busy as we are and I am good with just modifying the base class behavior with the workaround to make it all go away.

Thanks again for everything.

Hm, that is really surprising. I was really expecting the other controls on the form to have the same issue once you were not setting the font on them. 

The only other thing I can think of that makes the grid different in any way is the TextRenderingMode. That might be worth a try, just as a matter of curiosity.

Hello David,

I will try to reproduce this issue using Windows 10 1803 update.  Once I create a sample and observe this behavior, we will test it further to investigate what’s causing this. If you already have a sample, please send it to us. It will help us in investigating this issue faster.

I will post an update by end of day Thursday.

Please let me know if you have any questions.

The TextRenderingMode was set to Default, I tried both GDI and GDIPlus, but with the same errant results.