topic Re: How to acces to a layer in a groupLayer in Developers Questions

How to acces to a layer in a groupLayer

JonGarrido — Wed, 16 Jul 2014 08:28:38 GMT

Hi,

I'm attempting to access to a FeatureLayer in a GropuLayer. I'm looping through layers in the TOC and when getting the IGroupLayer I don't know what to do next.

IMap myMap = ArcMap.Document.ActivatedView.FocusMap;

for (int i = 0; i < myMap.LayerCount; i++)

{

if (myMap.Layer is IGroupLayer)

{

IGroupLayer igroup = myMap.Layer as IGroupLayer;

//what to do...

}

Re: How to acces to a layer in a groupLayer

JavierArtero — Wed, 16 Jul 2014 12:31:30 GMT

Two methods are available (as far as I know) to get a particular layer from the ToC.

1.- Traversing the Layer collection obtained from a Map instance

2.- Iterating the enumerator Layers obtained from a Map instance

The first, the one that you are showing on your code, forces you to deal with group layers. This is usually solved by using a recursive function.

If you are only interested on Feature layers, I would advise to face the problem busing the second option.

I'll give you a sample code in vb.net (which you should be able to translate to C# in a breeze)

Dim enumLayer As IEnumLayer
Dim uidGeo As UID = New UIDClass()
// GUID for IGeoFeatureLayer
uidGeo.Value = "{E156D7E5-22AF-11D3-9F99-00C04F6BC78E}"
// Request IGeoFeatureLayers recursing into group layers
enumLayer = FocusMap.Layers(uidGeo, True)

enumLayer.Reset()
// You will need a cast into IFeatureLayer here, since the enumLayer.Next returns a ILayer interface
Dim featureLayer as IFeatureLayer = enumLayer.Next

While featureLayer IsNot Nothing
     // Do whatever you need...

     // Next feature layer...
     featureLayer = enumLayer.Next()
End While

Hope this works for you.

PS: Group layers are better dealt with by using the ICompositeLayer interface, which will provide you with access to its contained layers. So instead of using the IGroupLayer, you should use the ICompositeLayer... in case you didn't like the solution I provided

Re: How to acces to a layer in a groupLayer

JonGarrido — Wed, 16 Jul 2014 12:38:19 GMT

Hi Alberto,

I haven't nay problem on looping through the "normal" layers of the TOC. Only with the ones are inside a group layer.

The groupeLayer responses like normal layer, but inside there can be multiple layers and I can't access to them...

Thanks for your response in any case...

Jon

Re: How to acces to a layer in a groupLayer

JavierArtero — Wed, 16 Jul 2014 12:59:20 GMT

Ok, i'll just modify your code replacing IGroupLayer for ICompositeLayer. Not my type of solution but I guess it'll do the job...

IMap myMap = ArcMap.Document.ActivatedView.FocusMap;

for (int i = 0; i < myMap.LayerCount; i++)

{

if (myMap.Layer is ICompositeLayer)

{

ICompositeLayer igroup = myMap.Layer as ICompositeLayer;

for (int j = 0; j < igroup.Count; j++)

{

IFeatureLayer ilayer = igroup.Layer(j) as IFeatureLayer;

// Do whatever you need.

}

Does it works for you now?

Re: How to acces to a layer in a groupLayer

JonGarrido — Wed, 16 Jul 2014 13:22:22 GMT

HI Javier,

I'll test it tomorrow. Thank you very much!!

Re: How to acces to a layer in a groupLayer

JonGarrido — Thu, 17 Jul 2014 10:52:39 GMT

Thanks to everybody,

Javier was true, ICompositeLayer gave me access to the layers inside the GroupLayer

Gracias Javier!!!