WPF Sizing a Border so it doesn't go out of view.. remains and fills the page

Hi..
I have border and in that border,  I have another border and in that I have textbox.
I need to keep the borders 'on the page' so that when the text gets huge thet borders remain filled on the page and don't go off the page and get cut off.  How can I size the borders so that they fill the whole  page when the text is large and how can I add scrollview

My current xaml looks like this


                <Border Grid.Row="1" x:Name="brdSearchResults" CornerRadius="3" Padding="5" Margin="10,10,10,10" BorderBrush="Blue"  BorderThickness="1" Background="White">
             
                    <StackPanel Orientation="Vertical">

                        <Border x:Name="brdUserNotesResults" CornerRadius="3" Grid.Row="1" Background="LightGray" BorderThickness="1,1,1,1" Margin="3,3,3,3">
                                                     
                            <StackPanel Orientation="Vertical">
                           
                            <TextBlock x:Name="txtResult"   Margin="5,0,5,5"  FontWeight="Bold"  HorizontalAlignment="Center" VerticalAlignment="Center" />

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