topic Re: Creating Nested Block in .NET Forum

Creating Nested Block

Anonymous — Wed, 18 Sep 2013 09:12:49 GMT

Hi,

Can Anyone help me with a sample code for creating nested blocks.

Thanks & Regards

Re: Creating Nested Block

philippe.leefsma — Tue, 24 Sep 2013 08:58:13 GMT

This sample creates a nested block that contains a circle, then a parent block that contains a block reference of the nested block:

[CommandMethod("NestedBlock")]
public void NestedBlock()
{
    Document doc = Application.DocumentManager.MdiActiveDocument;
    Database db = doc.Database;
    Editor ed = doc.Editor;

    using (Transaction Tx = db.TransactionManager.StartTransaction())
    {
        BlockTable bt = Tx.GetObject(db.BlockTableId, OpenMode.ForWrite) 
            as BlockTable;

        BlockTableRecord btr = new BlockTableRecord();

        btr.Name = "ParentBlock";

        bt.Add(btr);

        Tx.AddNewlyCreatedDBObject(btr, true);


        BlockTableRecord btrNested = new BlockTableRecord();

        btrNested.Name = "NestedBlock";

        bt.Add(btrNested);

        Tx.AddNewlyCreatedDBObject(btrNested, true);

        Circle circle = new Circle(Point3d.Origin, Vector3d.ZAxis, 5.0);

        AddToBlock(circle, btrNested.ObjectId);

        BlockReference bref = new BlockReference(
            Point3d.Origin, 
            btrNested.ObjectId);

        AddToBlock(bref, btr.ObjectId);

        Tx.Commit();
    }
}

private ObjectId AddToBlock(Entity entity, ObjectId btrId)
{
    using (Transaction tr = btrId.Database.TransactionManager.StartTransaction())
    {
        try
        {
            BlockTableRecord btr = tr.GetObject(
                btrId,
                OpenMode.ForWrite)
                    as BlockTableRecord;

            ObjectId id = btr.AppendEntity(entity);

            tr.AddNewlyCreatedDBObject(entity, true);

            tr.Commit();

            return id;
        }
        catch (Autodesk.AutoCAD.Runtime.Exception ex)
        {
            ErrorStatus es = ex.ErrorStatus;

            tr.Abort();
            return ObjectId.Null;
        }
        catch (System.Exception ex)
        {
            string error = ex.Message;

            tr.Abort();
            return ObjectId.Null;
        }
    }
}

Regards,

Philippe.

Re: Creating Nested Block

Anonymous — Tue, 24 Sep 2013 10:03:18 GMT

Hi,

Thanks for your time but when I executed the code no circle is visible in the drawing but when I click block editor the circle is displayed in both blocks. Please see attached image.

Re: Creating Nested Block

philippe.leefsma — Tue, 24 Sep 2013 11:29:42 GMT

The circle is not visible because the final block is not inserted in the drawing. If you want to see it in model space, you would need either to use INSERT command or insert it programmatically. The circle is displayed in both block because NestedBlock is nested in the ParentBlock, so this is the expected behavior.

If you are a beginer with the AutoCAD API, I suggest you take a look first at the following resources:

http://www.youtube.com/watch?v=WYj0J-DrCSA

http://usa.autodesk.com/adsk/servlet/index?id=18162650&siteID=123112

http://docs.autodesk.com/ACD/2013/ENU/index.html?url=files/GUID-4E1AAFA9-740E-4097-800C-CAED09CDFF12.htm,topicNumber=d30e712496

Regards,

Philippe.

Re: Creating Nested Block

Anonymous — Wed, 25 Sep 2013 06:14:07 GMT

That was great. The code that you gave answers what I asked for.

I was creating nested blocks so that when I take this file in Navisworks I could see a heirarchal tree structure like:

GreateGrandfather

Grandfather

Father

Child

Circle

But When I take this file in Navisworks I get the structure as:

GreateGrandfather

Grandfather

Father

Child

Circle

Please see the attached image[File in Navisworks]

Also When I try to run the code with some existing entity in the drawing and call AddToBlock with this existing entity as parameter in place of circlr its throws error eAlreadyindatabase at line :

tr.AddNewlyCreatedDBObject(entity, True)

And Yes you are right I have been in to programming from last 10 years but with AutoCAD API I have been working on and off for last 2 years.