topic Re: Convert DBObjectCollection to polyline in .NET Forum

Convert DBObjectCollection to polyline

youssefGC — Sat, 04 Feb 2023 18:50:51 GMT

Hello Forums,

I'm trying to work with "GetOffsetCurves()" in order to create a offset polyline(opened), but it return a DBObjectCollection. To convert this collections, I put a function :

public Polyline ConvertDBObjectToPolyline(Document doc, DBObjectCollection dbcol, Plane _plane) { Polyline _Pline = new Polyline(); Database db = doc.Database; Transaction tr =doc.TransactionManager.StartTransaction(); using (tr) { BlockTable bt =(BlockTable)tr.GetObject(db.BlockTableId,OpenMode.ForWrite); BlockTableRecord btr =(BlockTableRecord)tr.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite); // For initial Curve take the first in the list Curve cv1 = dbcol[0] as Curve; _Pline.AddVertexAt(_Pline.NumberOfVertices, cv1.StartPoint.Convert2d(_plane), BulgeFromCurve(cv1, false), 0, 0); _Pline.AddVertexAt(_Pline.NumberOfVertices, cv1.EndPoint.Convert2d(_plane), 0, 0, 0); dbcol.Remove(cv1); Point3d nextPt = cv1.EndPoint; int prevCnt = dbcol.Count + 1; while (dbcol.Count > 0 && dbcol.Count < prevCnt) { prevCnt = dbcol.Count; foreach (Curve cv in dbcol) { // If one end of the curve connects with the // point we're looking for... if (cv.StartPoint == nextPt || cv.EndPoint == nextPt) { // Calculate the bulge for the curve and // set it on the previous vertex double bulge = BulgeFromCurve(cv,false); _Pline.SetBulgeAt(_Pline.NumberOfVertices - 1, bulge); // Reverse the points, if needed if (cv.StartPoint == nextPt) nextPt = cv.EndPoint; else // cv.EndPoint == nextPt nextPt = cv.StartPoint; // Add out new vertex (bulge will be set next // time through, as needed) _Pline.AddVertexAt(_Pline.NumberOfVertices, nextPt.Convert2d(_plane), 0, 0, 0); // Remove our curve from the list, which // decrements the count, of course dbcol.Remove(cv); break; } } } tr.Commit(); } return _Pline; }

After debugging, it's doesn't march in all segments!

Re: Convert DBObjectCollection to polyline

Jeff_M — Sun, 05 Feb 2023 00:32:56 GMT

The DBObjectCollection from an offset polyline should only contain 1 object, a Polyline.

//crv is a Polyline object var offset = crv.GetOffsetCurves(15.0); var pline = (Polyline)offset[0];

Re: Convert DBObjectCollection to polyline

_gile — Sun, 05 Feb 2023 09:24:34 GMT

Hi,

More accurately, the GetOffsetCurves method returns a DBObjectCollection because offesting a curve may generate more than one curve. If the the source curve is a polyline, the generated curves are also polylines

(view in My Videos)

Your ConvertDBObjectToPolyline method could be simply like this:

public void ConvertDBObjectToPolyline(Database db, DBObjectCollection dbCol) { using (var tr = db.TransactionManager.StartTransaction()) { var modelSpace = (BlockTableRecord)tr.GetObject( SymbolUtilityServices.GetBlockModelSpaceId(db), OpenMode.ForWrite); foreach(Curve curve in dbCol) { modelSpace.AppendEntity(curve); tr.AddNewlyCreatedDBObject(curve, true); } tr.Commit(); } }

Re: Convert DBObjectCollection to polyline

youssefGC — Sun, 05 Feb 2023 10:47:50 GMT

That works, thanks a lot

Re: Convert DBObjectCollection to polyline

youssefGC — Sun, 05 Feb 2023 10:49:17 GMT

Yes, but I want to retrieve it as a polyline

Re: Convert DBObjectCollection to polyline

Jeff_M — Sun, 05 Feb 2023 16:04:02 GMT

@_gile correct, I knew there were cases where there may be multiples I just couldn't think of any examples last night. Thanks for the correction.