Example #1
0
        public void PprArc()

        {
            //准备工作

            Document doc = Application.DocumentManager.MdiActiveDocument;

            Database db = doc.Database;

            Editor ed = doc.Editor;

            Transaction trans = db.TransactionManager.StartTransaction();

            BlockTable bt = trans.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;

            BlockTableRecord btr = trans.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;



            PromptPointOptions ppo = new PromptPointOptions("");

            PromptPointResult ppr;

            Point3d temp = new Point3d();

            Point2d p1, p2;

            //获取两个点

            ppo.Message = "\n请输入第一个点:";

            do

            {
                ppr = ed.GetPoint(ppo);

                temp = ppr.Value;

                p1 = new Point2d(temp.X, temp.Y);
            } while (ppr.Status != PromptStatus.OK);



            ppo.Message = "\n请输入第二个点:";

            do

            {
                ppr = ed.GetPoint(ppo);

                temp = ppr.Value;

                p2 = new Point2d(temp.X, temp.Y);
            } while (ppr.Status != PromptStatus.OK);



            double L = p1.GetDistanceTo(p2);

            double R = 0;



            //获取半径

            do

            {//避免出现半径比弦长一半还小的情况出现
                PromptDoubleOptions pdo = new PromptDoubleOptions("\n最后,请输入半径:");

                PromptDoubleResult pdr = ed.GetDouble(pdo);

                if (pdr.Status == PromptStatus.OK)
                {
                    R = pdr.Value;
                }
            } while (R < L / 2);

            double H = R - Math.Sqrt(R * R - L * L / 4);



            Polyline poly = new Polyline();

            poly.AddVertexAt(0, p1, 2 * H / L, 0, 0);

            poly.AddVertexAt(1, p2, 0, 0, 0);

            btr.AppendEntity(poly);

            trans.AddNewlyCreatedDBObject(poly, true);

            trans.Commit();

            trans.Dispose();
        }