在Silverlight中单击HyperlinkBut​​ton时,如何避免出现蓝色边框？

   <Setter Property="Template">
       <Setter.Value>
           <ControlTemplate TargetType="HyperlinkButton">
                <Grid>
                   <VisualStateManager.VisualStateGroups>
                       <VisualStateGroup x:Name="CommonStates">
                           <VisualState x:Name="Normal" />
                           <VisualState x:Name="MouseOver" />
                           <VisualState x:Name="Pressed">
                               <Storyboard>
                                   <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="TextBlock">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneAccentBrush}" />
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                           <VisualState x:Name="Disabled">
                               <Storyboard>
                                   <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="TextBlock">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}" />
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <TextBlock x:Name="TextBlock" Text="{TemplateBinding Content}" />
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<HyperlinkButton Content="点击这里" Style="{StaticResource NoBorderHyperlinkButton}" />