AutoCAD 多重引线 文本 左右对齐的问题

        static void AddMleader(Point3d startPoint, Point3d endPoint, string textContents, double textWidth, double textHeight)
        {
            var doc = Application.DocumentManager.MdiActiveDocument;
            var db = doc.Database;
            var ed = doc.Editor;

            using (var tr = db.TransactionManager.StartTransaction())
            {
                var mleader = new MLeader();
                mleader.SetDatabaseDefaults();
                mleader.ContentType = ContentType.MTextContent;
                int index = mleader.AddLeader();
                mleader.AddLeaderLine(index);
                mleader.AddFirstVertex(index, startPoint);
                mleader.AddLastVertex(index, endPoint);

                MText mtext = new MText();
                mtext.SetDatabaseDefaults();
                mtext.Width = textWidth;
                mtext.Height = textHeight;
                mtext.Contents = textContents;

                mleader.MText = mtext;
                mtext.Location = mleader.TextLocation;
                if (endPoint.X < startPoint.X)
                {
                    var offset = (mleader.DoglegLength + mleader.LandingGap) * 2 + mtext.ActualWidth;
                    mleader.MoveMLeader(Vector3d.XAxis * -offset, MoveType.MoveContentAndDoglegPoints);
                }

                var cSpace = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite);
                cSpace.AppendEntity(mleader);
                tr.AddNewlyCreatedDBObject(mleader, true);
                tr.Commit();
            }
        }