topic Re: Display diameter of a circle as the user draws it in ArcGIS API for Silverlight Questions

Display diameter of a circle as the user draws it

TylerRothermund — Tue, 14 Feb 2012 20:31:19 GMT

How can I display the diameter of a circle as the user draws it ? I want the diameter to only be displayed while the user is drawing.

I'm using the code from this example to draw the circle.
I looked at using the MeasureAction but it seems like there must be a better way than watching the collection changed of the layers so i can create a new graphic that is the correct size, since there is no MeasureComplete event.

Re: Display diameter of a circle as the user draws it

TylerRothermund — Tue, 21 Feb 2012 01:03:22 GMT

Any suggestions?

Re: Display diameter of a circle as the user draws it

OrlandoCarvajal — Tue, 21 Feb 2012 14:25:32 GMT

I would try using the Draw.DrawBegin, Map.MouseLeftButtonDown and Map.MouseMove events in something like this:
1. In Map.MouseLeftButtonDown save the current cursor position.
2. In DrawBegin detect when the shape is a circle and start tracking the cursor's movement by attaching to the MouseMove event.
3. In the MouseMove, obtain the current position and convert it (along with the center's location) to map's coordinates. Then calculate the distance.
4. Add or move a text graphic in a Graphics layer showing the diameter (distance*2).
5. In DrawComplete detach from the MouseMove event.

Not sure if you in the DrawBegin event you can access the current Cursor's location; if so you could save step 1.

Good luck

Re: Display diameter of a circle as the user draws it

JenniferNery — Wed, 22 Feb 2012 16:52:50 GMT

We don't support this out-of-the-box so would require you to write your own code. Orlando's suggestion sound like a good solution. DrawBegin will not give you the current location but after this is raised, you can use VertexAdded event and get the start point from there.