I change values of points of a link in SelectionMoving event, then
call UpdateFromPoints method. Function can be done but the link
flickers seriously. How to solve it?

Thanks.

Stoyo wrote on Dec 12^th, 2012 at 9:48am:

Thanks. So I should call RecreateCacheImage after every time UpdateFromPoints is called ? or
just call it at anyplace of SelectionMoving event?

I call it like below:
...
shape.UpdateFromPoints(false, false);
this.DiagramView.RecreateCacheImage();
...

But it does not work and cause a new strange problem.

Stoyo wrote on Dec 13^th, 2012 at 7:15am:


Thanks for your reply.
I read the document, I still can not understand.
Looks behavior class only can work when user draw a shape.
But my case is not a operation of drawing a shape, it is
a operation of modifying a shape. Would you like tell me more ?

Thanks a lot

Thanks. Your answer is helpful. But I meet a new problem so I try to show you more and hope you will give me help again.

// This is only a base class, nothing else
public class EMLinkShape : DiagramLink
{
...
}
// This is the link that I want to control
public class EMLinkMessageShape : EMLinkShape
{
...
}
// My custom behavior class
internal class EMLinkMessageShapeBehavior : DrawLinksBehavior
{
     public EMLinkMessageShapeBehavior(DiagramView diagramView)
           : base(diagramView)
     {
     }
     // I override below three methods to implement my control
     // It can work.
     protected override DiagramLink CreateLink()
     {
           return new EMLinkMessageShape(this.Diagram);
     }
     protected override void OnMouseMove(Point mousePosition)
     {
           // Here call my method to draw link
           MyMethod(...);
     }
     public override InteractionState StartDraw(PointF point)
     {
           DiagramLink link = Diagram.GetLinkAt(point, this.Diagram.LinkHitDistance);

           if (link != null)
                 return new InteractionState(link, 8, Action.Modify);
           else
                 return new InteractionState(new ShapeNode(Diagram), -1, Action.Create);
     }
     // This is my method
     protected void MyMethod(...)
     {
           ...
           link.UpdateFromPoints(); // this is last line
     }
}

It can work and can finish my feature. But there is a new problem. When I modify link by mouse slowly, feature can be done excellently. But if I
move mouse quickly the result is very ugly. Like what the below picture shows


How to solve this problem?

It is hard to understand, InvalidRect of InteractionState is a value , not a list. How to add?
Could you show me a sample? just several lines code. Thanks a lot

BTW，There is another question. When I only select a shape(type is ShapeNode), then overrided method of my custom behavior class will be called. But if I choose several shape, such as 2 ShapeNode and a DiagramLink, then overrided method of my custom behavior class can not be called. Why? Thanks a lot

One more question. Is there any other documents or materials to train developers to use this product? I tried to registry twice but did not get any mail to activate my account. If there are some other documetns then please tell me download link. Thanks

StartDraw is not called always. Select several shapes then drag mouse starting at a empty point (no any shape under cursor), then StartDraw will be called. if a shape is under cursor and the shape is selected then StartDraw will not be called. So when user choose several shapes and try to move them then where is the best place to customize behaviour ?

Actually I found a way to do it in this situation but I am not sure it is the best way. When user choose single shape then create InteractionState object in StartDraw method then return to caller. If use select muliple shapes then I create a InteractionState obejct in OnMouseMove method and assign the object to Diagram object directly. Is it the only way ?

And I hope there are some documents to decribe how to use these classes in namespace MindFusion.Diagramming.WinForms.Behaviors.

Thanks a lot

Thanks very much.
I select a shape, such as a ShapeNode, then move it. I find OnMouseMove method will be called twice and the value of MouseMoved of InteractionState is false. I think only once is enough to notice developer that this is the moment to begin to move mouse. But actually it is twice, why?