Change color of border on CheckBox

[roxxel]

How can i change color of border on checkbox
(using BorderBrush i can change color, but that's not what i need)

[MarkusKgit]

Just an example (using Fluent Theme):

<Grid>
  <Grid.Styles>
    <Style Selector="CheckBox /template/ Border#NormalRectangle">
      <Setter Property="BorderBrush" Value="Red"/>        
    </Style>
    <Style Selector="CheckBox:pointerover /template/ Border#NormalRectangle">
      <Setter Property="BorderBrush" Value="Green" />
    </Style>
  </Grid.Styles>
  <CheckBox Content="Check me"/>
</Grid>

In addition to :pointerover you might want to also handle :pressed, :disabled, :checked, :checked:pointerover, :checked:pressed and :checked:disabled

[mikhailSokolovskiy]

how do I access the third state of the checkbox? when selected any itmes, like a rectangle instead tick

[thevortexcloud]

Check the original styles. I am guessing it's this:

Avalonia/src/Avalonia.Themes.Fluent/Controls/CheckBox.xaml

Lines 218 to 234 in fd15b6b

	<Style Selector="^:indeterminate">
	<!-- Indeterminate Normal State -->
	<Setter Property="Foreground" Value="{DynamicResource CheckBoxForegroundIndeterminate}" />
	<Setter Property="Background" Value="{DynamicResource CheckBoxBackgroundIndeterminate}" />
	<Setter Property="BorderBrush" Value="{DynamicResource CheckBoxBorderBrushIndeterminate}" />
	<Style Selector="^ /template/ Border#NormalRectangle">
	<Setter Property="BorderBrush" Value="{DynamicResource CheckBoxCheckBackgroundStrokeIndeterminate}" />
	<Setter Property="Background" Value="{DynamicResource CheckBoxCheckBackgroundFillIndeterminate}" />
	</Style>
	<Style Selector="^ /template/ Path#CheckGlyph">
	<Setter Property="Fill" Value="{DynamicResource CheckBoxCheckGlyphForegroundIndeterminate}" />
	<Setter Property="Data" Value="M1536 1536v-1024h-1024v1024h1024z" />
	<Setter Property="Width" Value="7" />
	<Setter Property="Opacity" Value="1" />
	</Style>

[VoidPlayz510]

I found doing this worked

<Style Selector="CheckBox:unchecked /template/ Border#NormalRectangle">
	      <Setter Property="BorderBrush" Value="Red"/>
</Style>
 <Style Selector="CheckBox:pointerover /template/ Border#NormalRectangle">
	<Setter Property="BorderBrush" Value="Green" />
</Style>