Silverlight Custom Cursor Re-visited

In Silverlight 4.0 application I needed to have a line follow the mouse for comparing between line charts.  I Googled Silverlight 4.0 custom cursor and number three on the results was my old-old blog post about a custom cursor I put into a drawing program.  That took me back a ways.  ha ha.

For this app, my needs are simple, heck, I don't even need to hide the cursor.  I just want a line to follow the cursor while the mouse is over a specific panel.  So here's how I did it.

1. I added a Path object to the XAML of my page.  This Path needs to be on top, so it's at the bottom of the XAML just before the closing </Grid>.  Visibility is turned off so it doean't intrude until needed.

   <Path Data="M122,198 L122,583.57233" Fill="#FF01010C" x:Name="cursorline"
                 Visibility="Collapsed" HorizontalAlignment="Left"  Grid.Row="1" 
                 Stretch="Fill" Stroke="Black" UseLayoutRounding="False" 
                 Width="1"/>

2. I added mouse move event handlers to the containing grid, called imaginatively LayoutRoot.

   <Grid x:Name="LayoutRoot" MouseEnter="LayoutRoot_MouseEnter" 
             MouseLeave="LayoutRoot_MouseLeave" 
             MouseMove="LayoutRoot_MouseMove">

3. In Mouse Enter event handler, I set the visibility of my path to Visible.
4. In Mouse Leave event handler, I set the visibility of my path to Collapsed.
5. In Mouse Move event handler, I set the margin of my path to line up with the horizontal position of my cursor.  Here's the code.

           private void LayoutRoot_MouseEnter(object sender, MouseEventArgs e)
           {
               cursorline.Visibility = System.Windows.Visibility.Visible;
           }
           private void LayoutRoot_MouseLeave(object sender, MouseEventArgs e)
           {
               cursorline.Visibility = System.Windows.Visibility.Collapsed;
           }
           private void LayoutRoot_MouseMove(object sender, MouseEventArgs e)
           {
              cursorline.Margin = new Thickness( e.GetPosition(LayoutRoot).X, 0, 0, 0);

Ok then. Have a great day.