How to Disable the default Dashed Focus Rectangle on WPF Controls

When a WPF control gains the focus, it displays a dashed box around itself to indicate that it has the focus. In some cases, the focus rectangle can detract from the design of the program.

To disable this box, add the attribute FocusVisualStyle="{x:Null}" to a control.

To re-enable it, set that attribute to a Style of your choice.
example:
<Style x:Key="ButtonStyle" TargetType="{x:Type Button}">
        <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
</Style>

-------- nJoy :-)