去除Coding4Fun中MessagePrompt的边框（Border）

在App.xaml文件中添加
xmlns:c4f="clr-namespace:Coding4Fun.Toolkit.Controls;assembly=Coding4Fun.Toolkit.Controls"

    <!--应用程序资源-->
    <Application.Resources>
<ControlTemplate x:Key="MsgPropmtNoBorder" TargetType="c4f:MessagePrompt">
            <Grid VerticalAlignment="Stretch">
                <Rectangle Fill="{StaticResource TransparentBrush}"/>
                <Border VerticalAlignment="Top" Margin="10" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="5" CornerRadius="10">
                    <StackPanel Margin="10">
                        <TextBlock Text="{TemplateBinding Title}" Margin="0,-10,-25,10" FontSize="30" TextWrapping="Wrap" FontFamily="Segoe WP Light"/>
                        <ContentPresenter Content="{TemplateBinding Body}"/>
                        <StackPanel Margin="0,10,0,0" Name="actionButtonArea" Orientation="Horizontal" HorizontalAlignment="Center"/>
                    </StackPanel>
                </Border>
            </Grid>
        </ControlTemplate>

    </Application.Resources>

后台添加：
MessagePrompt textBoxMsgPrompt = new MessagePrompt();
            textBoxMsgPrompt.Template = Application.Current.Resources["MsgPropmtNoBorder"] as ControlTemplate;