That is controls by the FocusVisualStyle of the associated control. Unfortunately, you cannot disable that globally for all controls using a single Style
or setting. Instead, you'd have to individually turn it off for every control type.
For example, you can include the following styles in your Application.Resources
to turn it off for the specified controls:
<Style TargetType="Button">
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
</Style>
<Style TargetType="RepeatButton">
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
</Style>
<Style TargetType="ToggleButton">
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
</Style>
<Style TargetType="TreeViewItem">
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
</Style>
<!-- ETC -->
But keep in mind, that if you use the Style
property on any of the controls or if you have any other implicit styles defined then those will prevent the styles above from being applied.
Or as Rachel point out, you could do this:
<Style x:Key="FrameworkElementStyleKey" TargetType="FrameworkElement">
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
</Style>
<Style TargetType="Button" BasedOn="{StaticResource FrameworkElementStyleKey}" />
<Style TargetType="RepeatButton" BasedOn="{StaticResource FrameworkElementStyleKey}" />
<Style TargetType="ToggleButton" BasedOn="{StaticResource FrameworkElementStyleKey}" />
<Style TargetType="TreeViewItem" BasedOn="{StaticResource FrameworkElementStyleKey}" />
<!-- ETC -->
Functionally, both approaches above have the same effect.