Zoom to union of multiple layers?

KarenEllett

I know how to zoom to the full extent of one layer.  However, I have three graphic layers that are created at the same time, and all three are displayed at the same time.  I would like to zoom to the full extent of all three.  Can anyone give me some help on how to do that?

Thanks!

AsserSwelam1

Hi Karen,

You can do that by looping over the three graphic layers you have and create a extent full all of them and zoom to that extent.

That will be done by comparing each XMin and Ymin of each of this graphic layers and the widest one of them (depend on the spatial reference you are using) you will use it as the XMin and YMin for a new created Envelope. Then do the same for the XMax and YMax.

Then zoom to that Envelope extent.

Same as this image

Lets say that your map have a base tiled layer and this 3 GraphicsLayers

you can achieve what you want by this code below

Envelope ZoomToExtent = new Envelope();

            for (int x = 1; x < 3; x++)

            {

                GraphicsLayer currentGLayer = MyMap.Layers as GraphicsLayer;

                for (int y = 1; y < 3; y++)

                {

                    GraphicsLayer comparedGLayer = MyMap.Layers as GraphicsLayer;

                    if (currentGLayer.FullExtent.XMax > comparedGLayer.FullExtent.XMax)

                        ZoomToExtent.Extent.XMax = currentGLayer.FullExtent.XMax;

                    if (currentGLayer.FullExtent.YMax > comparedGLayer.FullExtent.YMax)

                        ZoomToExtent.Extent.YMax = currentGLayer.FullExtent.YMax;

                    if (currentGLayer.FullExtent.XMin < comparedGLayer.FullExtent.XMin)

                        ZoomToExtent.Extent.XMin = currentGLayer.FullExtent.XMin;

                    if (currentGLayer.FullExtent.YMin < comparedGLayer.FullExtent.YMin)

                        ZoomToExtent.Extent.YMin = currentGLayer.FullExtent.YMin;

                } 

            }

            MyMap.ZoomTo(ZoomToExtent);

Hope that helps

Thanks,

Asser