Get Entity by using Entity Handle

[vkpunique]

I am looking for code to get entity from entity handle. I am write code to highligh blockreferences using it's entity handle. User will enter entity handle manually and It will highligh block reference if match is found.

I am confused how to approach this. Can i get object Id from entityhandle? or Can i get access to entity directly with entity handle?

Currently i am looping through all objects in drawing to find my match. I am looking for more efficient way to solve my problem.

[_gile · Accepted solution]

Hi,

You can use the Database.GetObjectId method or, better, the undocumented Database.TryGetObjectId one.

        [CommandMethod("TEST")]
        public static void Test()
        {
            var doc = Application.DocumentManager.MdiActiveDocument;
            var db = doc.Database;
            var ed = doc.Editor;
            var pr = ed.GetString("\nEnter Handle: ");
            if (pr.Status != PromptStatus.OK)
                return;
            if (long.TryParse(
                pr.StringResult,
                System.Globalization.NumberStyles.HexNumber,
                System.Globalization.CultureInfo.CurrentCulture,
                out long value))
            {
                if (db.TryGetObjectId(new Handle(value), out ObjectId id))
                {
                    if (id.ObjectClass.IsDerivedFrom(RXObject.GetClass(typeof(Entity))))
                    {
                        using (var tr = db.TransactionManager.StartTransaction())
                        {
                            var entity = (Entity)tr.GetObject(id, OpenMode.ForWrite);
                            entity.Highlight();
                            tr.Commit();
                        }
                    }
                    else
                    {
                        ed.WriteMessage("\nNot an entity Handle.");
                    }
                }
                else
                {
                    ed.WriteMessage("\nInvalid Handle.");
                }
            }
            else
            {
                ed.WriteMessage("\nNot an hex number");
            }
        }

[vkpunique]

Thanks Gile, That TryGetObjectId function looks like gem, I was wondering about it's compatibility with older version of autocad. 

One more question, for highlight object  editor.SetImpliedSelection(objectsIdArrary) is simpler or Entity.Highlight?

Currently I am using code below to get object ID, it's from Kean Walmsley blog.

private static ObjectId GetObjectIdFromDataBase(string entityHandle)
        {
            try
            {
                Document doc = Application.DocumentManager.MdiActiveDocument;
                Database database = doc.Database;

                //Convert Hexadecimal string to 64 bit integer
                long entityHandleLongInt = Convert.ToInt64(entityHandle, 16);

                //Create Handle from long integer
                Handle handle = new Handle(entityHandleLongInt);

                //Get Object Id for Handle
                ObjectId objectId = database.GetObjectId(false, handle, 0);

                return objectId;
            }
            catch (System.Exception)
            {
                return ObjectId.Null;
            }
        }

[_gile]

---

@vkpunique  a écrit :

I was wondering about it's compatibility with older version of autocad. 

---

It depends on what you mean with "older versions". If I remember well, it was available before A2013.

---

@vkpunique  a écrit :

One more question, for highlight object  editor.SetImpliedSelection(objectsIdArrary) is simpler or Entity.Highlight?

---

Entity.Highlight only highlights the entity (display effect) and do not 'select' it.

---

@vkpunique  a écrit :

Currently I am using code below to get object ID, it's from Kean Walmsley blog.

---

Using TryParse and TryGetObject is safer, overall if the handle has been entered by the user.

[vkpunique]

what's difference between highlight and selection? I just thought both are same thing. what's point of highlighting if you're not going to use it for other commands?

[_gile]

---

@vkpunique  a écrit :
what's difference between highlight and selection? I just thought both are same thing. what's point of highlighting if you're not going to use it for other commands?

---

Highlighting just change the entity appearance. It can be used to visually differentiate certain entities.

[_gile]

See the Entity.Highlight topic from the developper's documentation.