AutoCAD .Net 创建填充Hatch

以下代码展示：
往模型空间中添加填充对象。

using Autodesk.AutoCAD.Runtime;using Autodesk.AutoCAD.ApplicationServices;using Autodesk.AutoCAD.DatabaseServices;using Autodesk.AutoCAD.Geometry;using Autodesk.AutoCAD.EditorInput;using Autodesk.AutoCAD.Colors;[CommandMethod("NewHatch")]public static void NewHatch(){    Document doc = Application.DocumentManager.MdiActiveDocument;    Database db = doc.Database;    using (Transaction tr = db.TransactionManager.StartTransaction())    {        //-------------------------------        // 获取模型空间        //-------------------------------        BlockTable blockTbl = tr.GetObject(            db.BlockTableId, OpenMode.ForRead) as BlockTable;        BlockTableRecord modelSpace = tr.GetObject(            blockTbl[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;        //-------------------------------        // 创建圆作为填充的封闭边界        //-------------------------------        Circle circle = new Circle();        circle.Center = new Point3d(100, 100, 0);        circle.Radius = 50;        circle.Normal = new Vector3d(0, 0, 1);        modelSpace.AppendEntity(circle);        tr.AddNewlyCreatedDBObject(circle, true);        //-------------------------------        // 创建填充对象        //-------------------------------        Hatch hatch = new Hatch();        modelSpace.AppendEntity(hatch);        tr.AddNewlyCreatedDBObject(hatch, true);        hatch.SetHatchPattern(HatchPatternType.PreDefined, "ANSI31");        hatch.Associative = true;        ObjectIdCollection ids = new ObjectIdCollection();        ids.Add(circle.ObjectId);        hatch.AppendLoop(HatchLoopTypes.Outermost, ids);        hatch.EvaluateHatch(true);        //        tr.Commit();    }}