Remove strange behaviour from wpf button mouse-over - wpf

Question

I'm fighting with a dummy issue for hours.
In wpf I want to override the behaviour of a Button, and at the moment the basic behaviour I want is reached (a certain color).
But I'm not able to say simply: on mouseover add underline style!
I'm able to add underline but I'm not able to remove the square around the text!
The style I'm using is:
<Style TargetType="Button">
<Setter Property="Foreground" Value="{DynamicResource {x:Static vs_shell:EnvironmentColors.CommandBarMenuLinkTextBrushKey}}"></Setter>
<Setter Property="Cursor" Value="Hand"></Setter>
<Setter Property="Background" Value="Transparent"></Setter>
<Setter Property="BorderThickness" Value="0"></Setter>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock TextDecorations="Underline" Text="{TemplateBinding Content}" Background="Transparent"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
Any idea/suggestion?
Thanks!

Answer 1

Maybe this will help you :
Disable Control's Selection Background Effect in WPF
It concerns the ListViewItems, but you can apply this mechanism on buttons or any other WPF Controls.
Good luck

Answer 2

Add this setter to the style:
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
<ContentPresenter Margin="{TemplateBinding Padding}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>