Creating a block with multi-line attribute definition

By Balaji Ramamoorthy

Here is a sample code to create a block definition with multi-line attribute definition and to create a block reference from it.

internal static void CreateMyBlock()
{
    Database db 
        = Application.DocumentManager.MdiActiveDocument.Database;
 
    using (Transaction tr = db.TransactionManager.StartTransaction())
    {
        BlockTable bt = tr.GetObject(
                                        db.BlockTableId, 
                                        OpenMode.ForRead
                                    ) as BlockTable;
 
        if (bt.Has("MyBlock") == false)
        {
            bt.UpgradeOpen();
            BlockTableRecord btr = new BlockTableRecord();
            btr.Name = "MyBlock";
            btr.Origin = Point3d.Origin;
            bt.Add(btr);
            tr.AddNewlyCreatedDBObject(btr, true);
 
            // Attribute Definition
            AttributeDefinition attdef 
                = new AttributeDefinition
                        (
                            Point3d.Origin, 
                            @"MilliSecondsPSecondsPMinutes", 
                            "Time", 
                            "Time ?", 
                            db.Textstyle
                        );
            attdef.IsMTextAttributeDefinition = true;
            btr.AppendEntity(attdef);
            tr.AddNewlyCreatedDBObject(attdef, true);
        }
        tr.Commit();
    }
}
 
internal static void CreateMyBlockRef()
{
    Document doc = Application.DocumentManager.MdiActiveDocument;
    Database db = doc.Database;
    Editor ed = doc.Editor;
 
    PromptPointOptions ppo 
        = new PromptPointOptions("nSpecify insertion point :");
 
    PromptPointResult ppr = ed.GetPoint(ppo);
    if (ppr.Status != PromptStatus.OK)
        return;
 
    Point3d insertionPoint = ppr.Value;
 
    using (Transaction tr = db.TransactionManager.StartTransaction())
    {
        BlockTable bt 
            = db.BlockTableId.GetObject(OpenMode.ForRead) as BlockTable;
        BlockTableRecord blockDef 
            = bt["MyBlock"].GetObject(OpenMode.ForRead) as BlockTableRecord;
 
        BlockTableRecord ms 
            = bt[BlockTableRecord.ModelSpace].GetObject
                        (OpenMode.ForWrite) as BlockTableRecord;
 
        BlockReference blockRef 
            = new BlockReference(insertionPoint, blockDef.ObjectId);
 
        ms.AppendEntity(blockRef);
        tr.AddNewlyCreatedDBObject(blockRef, true);
 
        foreach (ObjectId id in blockDef)
        {
            DBObject obj = id.GetObject(OpenMode.ForRead);
            AttributeDefinition attDef = obj as AttributeDefinition;
            if ((attDef != null) && (!attDef.Constant))
            {
                AttributeReference attRef = new AttributeReference();
                attRef.SetAttributeFromBlock
                                (
                                    attDef, 
                                    blockRef.BlockTransform
                                );
                attRef.TextString = String.Format
                    (
                    @"MilliSeconds : {0}PSeconds : {1}PMinutes : {2}", 
                    DateTime.Now.Millisecond.ToString(), 
                    DateTime.Now.Second.ToString(), 
                    DateTime.Now.Minute.ToString()
                    );
 
                blockRef.AttributeCollection.AppendAttribute(attRef);
                tr.AddNewlyCreatedDBObject(attRef, true);
            }
        }
 
        tr.Commit();
    }
}
 
[CommandMethod("Test")]
static public void TestMethod()
{
    CreateMyBlock();
 
    CreateMyBlockRef();
}