Check if AutoCAD selection set contains FDO features?

[hence_the_name]

Hi,

is there a reliable way to check if selected objects are Map FDO features?

It seems no checking is done here:

http://adndevblog.typepad.com/infrastructure/2012/07/using-acmapfeatureentityservicegetselection-to-...

but checking is done here:

http://forums.autodesk.com/t5/AutoCAD-Map-3D-Developer/FDO-object-properties-through-GetEntity/td-p/...

which I haven't tried myself yet but it doesn't look right to me to rely on this construct:

if (ent.Layer!="*ACMAPDMGISENTITIES") ....

What I have is:

 MgSelectionBase selectionBase = AcMapFeatureEntityService.GetSelection(selSet);

but I need to filter out all non-FDO objects in "selSet". Any ideas?

many thanks,

Rob

[hence_the_name]

Hi,

my issue is actually slighty different then described above.

For me it doesn't matter if there are FDO and CAD objects mixed in the selection set. The problem arises if only CAD objects have been selected. I need to find out if that is the case. But I do not know how.

If only an ACAD object has been selected I get a System.NullReferenceException. So I added a check whether the object in question is null or not. But it doesn't seem to be null or my check is wrong?

MgSelectionBase selectionBase = AcMapFeatureEntityService.GetSelection(selSet);

if (selectionBase != null)

...//ok

else

 return; //stop

It never follows the Else branch - but then I get the aformentioned exception later on at

selectionBase.GetLayers().Count

Any ideas?

Rob

[jackie.ng · Accepted solution]

Unless AutoCAD Map has a radically different implementation of MgSelectionBase from MapGuide, the GetLayers() method of MgSelectionBase returns null for empty selections

So selectionBase.GetLayers() == null means no features selected

- Jackie

[hence_the_name · Accepted solution]

Hi Jackie,

many thanks - that's the solution,

Rob