Dynamic Block Hatch Not Updating to New Contour After Parameter Change

M_Kocyigit — Wed, 03 Sep 2025 06:29:37 GMT

I’m working with AutoCAD 2019 and insert dynamic blocks with visibility parameters via a .NET method, but the hatches do not automatically adjust to the new contour of the cross-section after parameter changes – is there a solution for this?

Re: Dynamic Block Hatch Not Updating to New Contour After Parameter Change

M_Kocyigit — Wed, 03 Sep 2025 06:00:22 GMT

After extensive research, I was finally able to solve the problem. The magic word is EvaluateHatch.

/// <summary> /// /// Re-evaluates all <see cref="Hatch"/> objects that belong to the block definition /// used by the given block reference, and marks the reference graphics as modified (regen). /// /// </summary> /// /// <param name="blockRefId"> /// /// ObjectId of the <see cref="BlockReference"/> to refresh. /// /// </param> public static void ReevaluateHatchesInBlock ( ObjectId blockRefId ) { if ( blockRefId.IsNull || blockRefId.IsErased || !blockRefId.IsValid ) { return; } var db = blockRefId.Database; using ( var tr = db.TransactionManager.StartTransaction() ) { var br = tr.GetObject ( blockRefId, OpenMode.ForRead, false ) as BlockReference; if ( br == null || br.IsErased ) { tr.Abort(); return; } var btr = tr.GetObject(br.BlockTableRecord, OpenMode.ForRead, false) as BlockTableRecord; if ( btr != null && !btr.IsErased ) { foreach (ObjectId entId in btr) { var hatch = tr.GetObject(entId, OpenMode.ForRead, false) as Hatch; if (hatch != null && !hatch.IsErased) { // Open in write mode to run EvaluateHatch hatch.UpgradeOpen ( ); hatch.EvaluateHatch ( true ); } } } // Refresh the display of the BlockReference br.UpgradeOpen ( ); br.RecordGraphicsModified ( true ); // br.Draw(); tr.Commit(); } }

topic Re: Dynamic Block Hatch Not Updating to New Contour After Parameter Change in .NET Forum

Dynamic Block Hatch Not Updating to New Contour After Parameter Change

Re: Dynamic Block Hatch Not Updating to New Contour After Parameter Change