You should nest the ScrollViewers
. Something like this:
<Grid
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<ScrollViewer>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition
Width="Auto"/>
<ColumnDefinition
Width="700"/>
</Grid.ColumnDefinitions>
<StackPanel>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">1</TextBlock>
</StackPanel>
<ScrollViewer
Grid.Column="1"
VerticalScrollBarVisibility="Disabled"
VerticalScrollMode="Disabled"
HorizontalScrollBarVisibility="Auto"
HorizontalScrollMode="Auto"
ZoomMode="Disabled">
<StackPanel>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
<TextBlock Margin="10,10,50,10" FontSize="24">A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. A very long text. </TextBlock>
</StackPanel>
</ScrollViewer>
</Grid>
</ScrollViewer>
</Grid>