How to Insert Dynamic Blocks with Attributes in AutoCAD via C# Without Using ATTSYNC

Question

I'm programmatically inserting 1,000+ dynamic blocks of the same type into AutoCAD using C#. Each block has multiple attributes and dynamic properties (e.g., scale, rotation, custom values).

The insertion routine works quite efficiently — about 15 blocks per second — as long as I don't use ATTSYNC.

However, running ATTSYNC (via command call) after the insertions causes a massive slowdown:

It adds 7 to 10 minutes to the total execution time. Sometimes it even causes AutoCAD to freeze or become unresponsive.

I understand that ATTSYNC is required to refresh the attributes so that they appear correctly, but this is becoming a serious bottleneck.

Is there any way to avoid using ATTSYNC when inserting dynamic blocks programmatically? Or is there a faster or safer method to force the attributes to show up immediately after block insertion?

Any tips or workarounds would be greatly appreciated.

public object[,] DibujarDB(string blkName, string[] propsName, object[,] propsValue, ActualizadorFormulario actualizador)
{
    var doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;
    var db = doc.Database;
    var ed = doc.Editor;

    using (var trans = db.TransactionManager.StartTransaction())
    {
        try
        {
            var bt = (BlockTable)trans.GetObject(db.BlockTableId, OpenMode.ForRead);
            if (!bt.Has(blkName))
            {
                ed.WriteMessage($"\nEl bloque '{blkName}' no existe.");
                return null;
            }

            var btr = (BlockTableRecord)trans.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
            var lt = (LayerTable)trans.GetObject(db.LayerTableId, OpenMode.ForRead);

            int rows = propsValue.GetLength(0);
            int insertedCount = 0;
            string miEstado;
            var blkId = bt[blkName];
            var propIndices = propsName
                .Select((name, index) => new { name, index })
                .ToDictionary(p => p.name, p => p.index);

            int idxDibujar = propIndices["DIBUJAR"];
            int idxHandler = propIndices["HANDLER"];
            int idxCX = propIndices["CX"];
            int idxCY = propIndices["CY"];
            int idxCZ = propIndices["CZ"];
            int idxANG = propIndices["ANG"];
            int idxCAPA = propIndices["CAPA"];
            int idxESCX = propIndices["ESCX"];
            int idxESCY = propIndices["ESCY"];
            int idxESCZ = propIndices["ESCZ"];

            RevisionCapas(trans, lt, idxCAPA, propsValue);

            string[] dynPropNames = propsName.Skip(11).ToArray();

            for (int i = 0; i < rows; i++)
            {
                var dibujarVal = propsValue[i, idxDibujar]?.ToString();
                if (!string.Equals(dibujarVal, "SI", StringComparison.OrdinalIgnoreCase) &&
                    !string.Equals(dibujarVal, "TRUE", StringComparison.OrdinalIgnoreCase))
                {
                    continue;
                }

                if (!double.TryParse(propsValue[i, idxCX]?.ToString(), out double cx) ||
                    !double.TryParse(propsValue[i, idxCY]?.ToString(), out double cy) ||
                    !double.TryParse(propsValue[i, idxCZ]?.ToString(), out double cz) ||
                    !double.TryParse(propsValue[i, idxANG]?.ToString(), out double ang) ||
                    !double.TryParse(propsValue[i, idxESCX]?.ToString(), out double escX) ||
                    !double.TryParse(propsValue[i, idxESCY]?.ToString(), out double escY) ||
                    !double.TryParse(propsValue[i, idxESCZ]?.ToString(), out double escZ))
                {
                    ed.WriteMessage($"\nError: Datos inválidos en la fila {i}");
                    continue;
                }

                string capa = propsValue[i, idxCAPA]?.ToString() ?? "0";

                var blkRef = new BlockReference(new Point3d(cx, cy, cz), blkId)
                {
                    Rotation = ang,
                    ScaleFactors = new Scale3d(escX, escY, escZ),
                    Layer = capa
                };

                btr.AppendEntity(blkRef);
                trans.AddNewlyCreatedDBObject(blkRef, true);
                propsValue[i, idxHandler] = blkRef.Handle.ToString();

                foreach (var propName in dynPropNames)
                {
                    DynamicBlockReferenceProperty prop = blkRef.DynamicBlockReferencePropertyCollection
                        .Cast<DynamicBlockReferenceProperty>()
                        .FirstOrDefault(p => p.PropertyName == propName);

                    if (prop != null)
                    {
                        var valStr = propsValue[i, propIndices[propName]]?.ToString();
                        if (valStr != null && prop.Value.ToString() != valStr)
                        {
                            try
                            {
                                prop.Value = Convert.ChangeType(valStr, prop.Value.GetType());
                            }
                            catch
                            {
                                ed.WriteMessage($"\nAdvertencia: No se pudo asignar '{valStr}' a la propiedad '{propName}' en fila {i}");
                            }
                        }
                    }
                }

                insertedCount++;
                actualizador.ActualizarProgresoProceso();
            }

            trans.Commit();

            miEstado = "Toca sincronizar el bloque y eso demora, pa'.";
            actualizador.ActualizarEstado(miEstado);
            ed.Command("._ATTSYNC", "_N", blkName);
            miEstado = "Mucho atributo, llave. Mucho hijueputa atributo.";
            actualizador.ActualizarEstado(miEstado);
            return propsValue;
        }
        catch (System.Exception ex)
        {
            ed.WriteMessage($"\nError: {ex.Message}");
        }

        return null;
    }
}

gileCAD · Accepted Answer · 2025-06-15 05:50:46Z

1

You should explicitly add the attribute references to each inserted block reference instead of calling ATTSYNC.

Get the attribute definitions from the block definition:

// [...]
var blkId = bt[blkName];
var propIndices = propsName
    .Select((name, index) => new { name, index })
    .ToDictionary(p => p.name, p => p.index);

var blkDef = (BlockTableRecord)trans.GetObject(blkId, OpenMode.ForRead);
var attDefs = blkDef
    .Cast<ObjectId>()
    .Where(id => id.ObjectClass.Name == "AcDbAttributeDefinition")
    .Select(id => (AttributeDefinition)trans.GetObject(id, OpenMode.ForRead))
    .Where(attDef => !attDef.Constant)
    .ToArray();
// [...]

Add the attribute references for each newly created block reference:

// [...]
btr.AppendEntity(blkRef);
trans.AddNewlyCreatedDBObject(blkRef, true);
propsValue[i, idxHandler] = blkRef.Handle.ToString();

foreach (var attDef in attDefs)
{
    var attRef = new AttributeReference();
    attRef.SetAttributeFromBlock(attDef, blkRef.BlockTransform);
    blkRef.AttributeCollection.AppendAttribute(attRef);
    trans.AddNewlyCreatedDBObject(attRef, true);
}
// [...]

answered Jun 15 at 5:50

gileCAD

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1 Comment

Julián Felipe Herrera Mejía Jun 18 at 18:32

Thanks a lot for your answer. It worked perfectly. Now i'm having issues with the attribute value because I need to use some fields from the blockplaceholder but I will ask another question for that! Thanks a lot.

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