How to use GetObject() to identify an entity's type via this entity's ObjectId?

[Anonymous]

Hello,I don't fully understand what an objetctId is,and how to make good full use of an ObjectId.How to use the GetObject() method.For example,I create a polyline and add this polyline to an ObjectIdcollection.Now,how can I identify this polyline via the ObjectId?

[SRSDS]

Try this

Dim obj As DBObject = tr.GetObject(ObjId, OpenMode.ForRead)
Dim lwp As Polyline = TryCast(obj, Polyline)
If lwp IsNot Nothing Then
'...
End If

[StephenPreston]

Opening an object just to check its object type (to know if you should have opened it) is very time consuming if you're iterating over a large drawing. ObjectId exposes the ObjectClass property so you can check the RXClass of the DbObject the ObjectId is associated with.

[jeff]

Look at the arxdoc.chm in the docs folder in the ObjectARX SDK.

In the index tab type ObjectID and select about ObjectId structure. It will give you a good explanation.

When you create a polyline it's objectId is returned when you use BlockTableRecord.AppendEntity