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    <p><strong>Efficiency considerations of a two-panel approach vs DrawingContext</strong></p> <p>I have good news for you: You are wrong about the significant performance hit. Your two-canvas idea is nearly optimal, even if you use individual objects for the grid lines. This is because WPF uses retained-mode rendering: When you create the canvas, everything on it is serialized into a compact structure at native level. This only changes when you change the grid lines in some way, such as changing the grid spacing. At all other times the performance will be indistinguishable from the very fastest possible managed-code methods.</p> <p>A slight performance increase could be had by using <code>DrawingContext</code> as Nicholas describes.</p> <p><strong>A simpler and more efficient solution</strong></p> <p>Perhaps a better way then drawing individual lines on the grid canvas is to use two tiled visual brushes (one horizontal, one vertical) to draw all unhilighted lines, then use <code>Rectangle</code>(s) added in code-behind to hilight the line(s) you are snapping to.</p> <p>The main advantage of this technique is that your grid can be effectively infinite, so there is no need to calculate the right number of grid lines to draw and then update this every time the window resizes or the zoom changes. You also only have three UIElements involved, plus one more for each grid line that is currently hilighted. It also seems cleaner to me than tracking collections of grid lines.</p> <p>The reason you want to use two visual brushes is that drawing is more efficient: The brush drawing the vertical lines is stretched to a huge distance (eg double.MaxValue/2) in the vertical direction so the GPU gets only one drawing call per vertical line, the same for the horizontal. Doing a two-way tiling is much less efficient.</p> <p><strong>Adorner layer</strong></p> <p>Since you asked about alternatives, another possibility is to use <code>Adorner</code> and <code>AdornerLayer</code> with any of the solutions above rather than stacking your canvas using eg a Grid or containing Canvas. For a Paint-like application this is nice because the adorner layer can be above your graphic layer(s) yet the adorners can still attach to individual items that are being displayed.</p>
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    1. COI don't really understand your idea with 2 visual brushes. Can you be more specific? I didn't even know there was a way to use 2 different visual brushes on one pane.
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      1. USchrischu
    2. COIf you're using `<Rectangle ... Fill="{StaticResource GridBrush}" />` you can replace it with `<Grid><Rectangle ... Fill="{StaticResource HorizBrush}"/><Rectangle ... Fill="{StaticResource VertBrush}"/></Grid>` to draw two rectangles each with its own Visual Brush. HorizBrush will be transparent except for a gridline-width area at the top and VertBrush will be transparent except for a gridline-width area at the left. Viewport/Viewbox and tiling will be set so that each brush is repeated at the appropriate gridline interval in the given direction, creating a grid.
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    3. CONote that there may be more efficient ways to do the layout than using a separate `<Grid>`. For example, there may be an existing `<Grid>` you can share, or a `<Canvas>`.
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