How do I adjust the graph with scroll viewer in WPF

Question

I am getting the required output graph from my C# code.

 

The graph length is very big and I am only able to view some part of it.

 

I tried to use ScrollViewer. But I cannot see the ScrollViewer. Also I am getting the trimmed graph.

 

Please have a look at UI code.

 

The user first clicks on Button. Then he selects the file from dialog box.

 

Then a graph is drawn from the data of that file...

 

<Window Title="MainWindow" Height="500" Width="800">

<StackPanel Orientation="Vertical">

<Button Content="Select File" Height="32" Width="88" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="20,10,10,10" Name="button1" Click="button1_Click" />

<ScrollViewer Height="1800" Width="2000" CanContentScroll="True" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">

<Canvas x:Name="front_canvas" Height="auto" Width="auto"/>

</ScrollViewer>

</StackPanel>

</Window>