topic Re: Measure Action Does Not Always Give Correct Area in ArcGIS API for Silverlight Questions

Measure Action Does Not Always Give Correct Area

RyanCoodey — Fri, 01 Oct 2010 22:54:14 GMT

The best way to describe this is by looking at the attached two screen shots... The one that is a square has the correct area, but the one that obviously should be larger, is actually smaller... The line distances seem just fine, but the area is not correct... seems to be when the polygon is more convex. Is this a bug?

Thanks!

Re: Measure Action Does Not Always Give Correct Area

AliMirzabeigi — Wed, 06 Oct 2010 15:45:37 GMT

Ryan,

Thank you so much for your report. We are currently looking into this problem.

Re: Measure Action Does Not Always Give Correct Area

Anonymous User — Wed, 13 Oct 2010 20:28:21 GMT

Original User: rcoodey

Thanks Ali,

Another issue I found with the measure tool and it seems only when:
MeasureAction.MeasureMode = ESRI.ArcGIS.Client.Actions.MeasureAction.Mode.Polygon;
If you double click right away (i.e. the length is 0 and the area is 0) it crashes with "Object reference not set to an instance of an object"

A few other requests I have for the Measure Action in the future too
1) The distance unit is labeled for the totals (ie. feet, miles, etc) but not for the individual lines.
- For example, I am in polygon mode, and the area is labeled as Acres, which is great, but I don't have a label letting me know the lines are Feet.
2) The ability to programmatically cancel/quit a measure action. This has been asked by me and several others in other posts as well.

Thanks a lot for the help!!!

Re: Measure Action Does Not Always Give Correct Area

ChristineZeller — Wed, 13 Oct 2010 21:05:25 GMT

Ryan,

It sounds like you have got the measure area tool down. Sorry to cross my post with yours but I was wondering if you had time to quickly help me with my problem. I just can't seem to get it.

http://forums.arcgis.com/threads/14730-Area-And-Perimeter

Thanks and Sorry.

Re: Measure Action Does Not Always Give Correct Area

Anonymous User — Wed, 13 Oct 2010 21:36:47 GMT

Original User: rcoodey

I looked through your issue... I'm not using a Geometry Service but using a MeasureAction... this action takes care of the conversion for me, I just have to specify a few properties:

MeasureAction.AreaUnit = ESRI.ArcGIS.Client.Actions.AreaUnit.Acres;
MeasureAction.DistanceUnit = ESRI.ArcGIS.Client.Actions.DistanceUnit.Feet;
MeasureAction.MapUnits = DistanceUnit.DecimalDegrees;

MesureAction is not in the toolkit though or I would say go and look at the source for it and see what it is doing for conversions... As far as I know, the source for the API is not available though :(.

I have never used the AreasAndLengths Geometry Service, but I wonder if the Area calculation issue is similar/related to my above issue...

Sorry for not helping much 😞

Re: Measure Action Does Not Always Give Correct Area

DeryckMills — Fri, 05 Nov 2010 11:30:10 GMT

Ryan,

Thank you so much for your report. We are currently looking into this problem.

Any luck with a fix for this problem. Am also having the same issue.

Thanks