topic Re: Graphic objects disappearing when zoom-in/out in ArcGIS API for Silverlight Questions

Graphic objects disappearing when zoom-in/out

Anonymous User — Thu, 25 Nov 2010 07:02:49 GMT

Original User: bern2rd

We are experiencing this problem consistently where our graphic elements in the GraphicLayer sometime disappear when we zoom-in and out. In our example (see attachments) we have seven graphic items highlighted in the color green but for some reason one of them sometime does not show after we zoom-in (three or four times) and zoom-out (one time). There's definitely a problem in the rendering of the graphic layers.

If someone have had this problem or seen it please help.

Thank you,
Bernard

Re: Graphic objects disappearing when zoom-in/out

DominiqueBroux — Thu, 25 Nov 2010 18:06:26 GMT

Are you experiencing this problem only when the map is rotated or can you reproduce it even when the rotation is not set?

Re: Graphic objects disappearing when zoom-in/out

Anonymous User — Sun, 28 Nov 2010 19:19:30 GMT

Original User: bern2rd

I removed this line and it fixed the problem.

//myMap.ZoomDuration = TimeSpan.Zero;

This line was added because it solved the problem where when we set the extent constraint the zoom-in feature started to behave strangely. When clicked on the Zoom-Extent it goes to the full extent without a problem but as soon as you start zooming in it will not response. This problem goes away after you attempt to zoom-in about 5-6 times. When I removed this extent constraint everything worked flawlessly but of course without the constraint that we need.

FullExtent.ConstrainedExtent = fullExtentEnvelope;

btw, it has nothing to do with the rotation.

Thanks,
Bernard

Re: Graphic objects disappearing when zoom-in/out

JenniferNery — Mon, 29 Nov 2010 16:41:51 GMT

What version of the API are you using?

There is a known issue in v2.1 and lower that when Map's ZoomDuration is zero, the ConstrainedExtent is not respected.

I have not seen graphics disappear though. Can you share us your code? Maybe we can reproduce it here? Thanks.

Re: Graphic objects disappearing when zoom-in/out

Anonymous User — Wed, 01 Dec 2010 15:36:31 GMT

Original User: bern2rd

We're currently using API v2.0. I didnt even know there's v2.1 until you mentioned it.

Although I'm still experiencing the problem where it does not want to zoom-in when I have this set.

FullExtent.ConstrainedExtent = fullExtentEnvelope;

Should I upgrade to v2.1?

Thanks,
Bernard

Re: Graphic objects disappearing when zoom-in/out

JenniferNery — Wed, 01 Dec 2010 17:06:05 GMT

I am confused. Are you using ConstrainExtentBehavior?
http://help.arcgis.com/en/webapi/silverlight/apiref/ESRI.ArcGIS.Client.Behaviors~ESRI.ArcGIS.Client.Behaviors.ConstrainExtentBehavior.html

What type of layer are you using? Is FullExtent a property of this layer or is it the behavior?

FullExtent in the layers is of type Envelope. Have you checked these values in debug mode? Does your map respect this constrain? I don't see why you will have a problem "zooming in." If you try this sample: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#ConstrainExtentBehavior. The ConstrainExtent does not allow you to zoom out further than the given constrain, but it allows you to zoom in.

I would upgrade to v2.1 but I also want to understand the problem.