I think you will get layouts like this with the default LayeredLayout settings. You could also experiment with these LayeredLayout properties:

- StraightenLongLinks: ensures that there are no more than two bends per link, and tries to set as much vertical links as possible
- EnforceLinkFlow: assigns nodes to layers in such a way that all links flow in the same direction (possible only if the graph is acyclic).
- StartNode and EndNode: if you need specific nodes to be placed on the first/last layer

If you prefer to have single-segment diagonal links after FlowchartLayout or LayeredLayout, you can loop over all links and reset their SegmentCount to 1 after applying the layout:

layout.Arrange(diagram);

foreach (DiagramLink link in diagram.Links)
{
    link.AutoRoute = false;
    link.SegmentCount = 1;
} 

You can further ensure that links connect to the top or bottom sides of node either by using anchor points, or by manually setting ControlPoints[0] and ControlPoints[count - 1] positions. E.g. in the same loop check if (point0.X == srcRect.Left || point0.X == srcRect.Right), and move the control point somewhere along the source node's bottom border; also add a symmetric case for the last point and the link's destination.

I hope that helps,
Stoyan

Hi,

The compiler just prevents against losing the assigned X value silently; since Point is a value type, the indexer returns a temporary stack value whose X member change would be lost if you don't assign the point back. Whereas if Point was a reference type, setting X on the returned reference would change the original object. So replace this line:

link.ControlPoints[0].X = (link.Origin.Bounds.Right - link.Origin.Bounds.Left) / 2; 

with

PointF point = link.ControlPoints[0];
point.X = (link.Origin.Bounds.Right - link.Origin.Bounds.Left) / 2;
link.ControlPoints[0] = point; 

and this should compile successfully. However I think you should set X = (Right + Left) / 2 if you want to center it, instead of (Right - Left) / 2, and also set point.Y = Bottom to align the link to the node's bottom border.

I hope that helps,
Stoyan

As a result of your insightful suggestions, we have built a gorgeous Layered graph (see screenshot).

One question that has come up multiple times is:

Is there any way to prevent all links on the graph from intercepting with any of the nodes?

In the attached screenshot, there's one link that falls behind a node. I have actually noticed that it's unpredictable when a link may be drawn on top of a node or fall behind it, so in order to deal with that, I have explicitly set the ZIndex of all nodes and links so that links always end up under the nodes...But it would be better if they never intercepted.

I look forward to your helpful recommendations! And thank you for your time & help!

These are really great options - thanks!

So, what I did first was I took out all of the customization code that I wrote on top of the default LayeredLayout because I wanted to confirm that links won't intersect with any nodes based on what you said:

Quote:


But I found that to be untrue - screenshot attached.

This is the current definition of the LayeredLayout without any extra customizations (such as setting SegmentCount to 1 or moving any of the control points to a new position):

LayeredLayout ll = new LayeredLayout();
ll.Orientation = MindFusion.Diagramming.Layout.Orientation.Vertical;
ll.Anchoring = Anchoring.Reassign;
ll.Direction = Direction.Straight;
ll.LinkType = LayeredLayoutLinkType.Straight;
ll.SplitLayers = true;
ll.NodeDistance = 50f;
ll.LayerDistance = 25f;
ll.Arrange(PFVDiagram.Diagram);
 

Would any of the above settings be the reason why links are still crossing nodes?

Thank you!

So, it sounds like the Layered layout doesn't have a predictable behavior when we're talking about links crossing nodes. Even if I increased the LayerDistance for this particular graph, there still may be a case where this distance may not be sufficient and result in links nabbing the edge(s) of a node. By default, the algorithm has built-in logic to avoid crossing with other edges, but not with nodes unfortunately for my use case (from documentation):

Quote:


I will often have graphs containing links that cross multiple layers (as shown in my screenshots above), and it sounds like the only reliable way to avoid interception with other nodes is to write custom logic that analyzes each of the links and readjusts the nodes on each layer...which I would expect to have an impact on performance in some situations.

Wow! How are you achieving that? Would you mind posting some code OR reviewing mine below please?

In my graph, I haven't been able to generate that layout whatever I do (see screenshot). The link on left keeps nabbing (even barely) the leftmost node...

Here is my code that sets up the LayeredLayout:

LayeredLayout l4 = new LayeredLayout();
l4.Orientation = MindFusion.Diagramming.Layout.Orientation.Vertical;
l4.Anchoring = Anchoring.Reassign;
l4.Direction = Direction.Straight;
l4.LinkType = LayeredLayoutLinkType.Straight;
l4.SplitLayers = true;
l4.NodeDistance = 50f;
l4.LayerDistance = 35f;
l4.Arrange(PFVDiagram.Diagram);

foreach (DiagramLink link in PFVDiagram.Diagram.Links)
{
    System.Drawing.PointF startPoint = link.ControlPoints[0];
    startPoint.Y = link.Origin.Bounds.Bottom + 0.5f;
    // center link's exit point on bottom of node
    startPoint.X = (link.Origin.Bounds.Left + link.Origin.Bounds.Right) / 2;
    link.ControlPoints[0] = startPoint;

    System.Drawing.PointF endPoint = link.ControlPoints[link.ControlPoints.Count - 1];
    endPoint.Y = link.Destination.Bounds.Top - 0.5f;
    // center link's entry point on top of node
    endPoint.X = (link.Destination.Bounds.Left + link.Destination.Bounds.Right) / 2;
    link.ControlPoints[link.ControlPoints.Count - 1] = endPoint;

    // it doesn't seem to make any difference if I call this method or not
    link.UpdateFromPoints();
}
 

Thank you for your feedback - I really appreciate it!