WPF on .NET 8.0 > TextBox.SpellCheck custom dictionary has no effect

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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[severity:I'm unable to use this version] Hello,

I am currently facing the problem that the SpellCheck of the TextBox WPF-Control does not seem to load my lexicon file correctly.

Per documentation I am using the following code to load the dictionary:

txtContent.Language = System.Windows.Markup.XmlLanguage.GetLanguage("de-DE");
txtContent.SpellCheck.CustomDictionaries.Clear();
txtContent.SpellCheck.CustomDictionaries.Add(new Uri(@"C:\temp\test.lex", UriKind.Absolute));
txtContent.SpellCheck.IsEnabled = true;

The TextBox is defined in XAML as follows:

<TextBox x:Name="txtContent" DockPanel.Dock="Top"
         BorderThickness="0"
         Margin="0,0,0,0" Width="Auto" Height="Auto"
         SpellCheck.IsEnabled="false"
         IsInactiveSelectionHighlightEnabled="true"
         AcceptsReturn="True" AcceptsTab="True"
         Visibility="Visible"
         VerticalScrollBarVisibility="Auto" TextChanged="txtContent_TextChanged"
         SelectionChanged="TextBox_SelectionChanged" IsReadOnlyCaretVisible="True"
         ScrollViewer.ScrollChanged="txtContent_ScrollViewer_ScrollChanged"
         PreviewMouseWheel="txtContent_PreviewMouseWheel">
</TextBox>

The file "test.lex" contains the following lines:

#LID 1031
Datenbox
Dokumentenboard
Infoboard

Still, when I type the word "Datenbox" in the TextBox control, it underlines the word and tries to correct it.

When I retrieve the custom dictionaries using "SpellCheck.GetCustomDictionaries", I can see that the dictionary was in fact loaded. It just isn't applied for some reason.

Project Information:

<TargetFramework>net8.0-windows10.0.22621.0</TargetFramework>
<Nullable>enable</Nullable>
<ImplicitUsings>enable</ImplicitUsings>
<UseWPF>true</UseWPF>
<PlatformTarget>x64</PlatformTarget>

Any help or hints would be greatly appreciated!

Kind regards, Lukas

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Original Comments

Feedback Bot on 9/11/2024, 07:10 AM:

(private comment, text removed)

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Original Solutions

(no solutions)

[miloush]

Do you have a repro project?

[LukinTV]

@miloush I created a public repo with a minmal reproducible sample, you can find it here: https://github.com/LukinTV/WPF-SpellCheck-CustomDictionary.

Just be sure to change the absolute path to the .lex-file to wherever you cloned to project: txtSpellCheck.SpellCheck.CustomDictionaries.Add(new Uri(@"C:\temp\Repro\WPF-SpellCheck-CustomDictionary\custom.lex", UriKind.Absolute));

[lindexi]

Reference https://github.com/dotnet/wpf/issues/9701

[LukinTV]

Reference #9701

Also, https://stackoverflow.com/questions/77258504/wpf-spellcheck-on-windows-11-systems/. This seems to be a common problem.

[lindexi]

I've tried to investigate the problem, but I've had no luck

[alraseensaad]

Even with default spell check it sometimes works and sometimes not

[tualatin]

We have exact the same issue! Custom dictionaries are ignored in Windows 11, in Windows 10 all works fine. Any solutions for that issue?

[lindexi]

@tualatin Sorry, I can not find any solution.

[garzooma]

I duplicated this issue using the WPF-Samples code in[https://github.com/microsoft/WPF-Samples/archive/refs/heads/main.zip], with the project in Documents/Spell Checking/CustomDictionaries. The textbox spellchecking pays no attention to the sample CustomDictionary.lex file.

[h3xds1nz]

@garzooma Can you share the OS version you've replicated it on?

[garzooma]

@garzooma Can you share the OS version you've replicated it on?

Edition Windows 11 Pro Version 24H2 Installed on ‎2/‎6/‎2025 OS build 26100.3194 Experience Windows Feature Experience Pack 1000.26100.48.0

[dev-3mensio]

We are seeing this issue too in a net 8 app on current windows 11 builds. The issue being that we do enable spell checking in WPF controls, we have persistent custom dictionaries, and these custom dictionaries are ignored.