autocad.net中blocktable,blocktablerecord,blockreference,modelspace,paperspace,layout,viewport的关系（待进一步测试）

        [CommandMethod("test")]
        public static void test()
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;
            Editor ed = doc.Editor;
            //定义所有的视口ID集合
            ObjectIdCollection viewportIDs = new ObjectIdCollection();
            viewportIDs = db.GetViewports(true);
            List<ObjectId> objectsIdsErase = new List<ObjectId>();
            PromptEntityOptions peo = new PromptEntityOptions("\n请选择一个视口！");
            peo.SetRejectMessage("\n当前选择的图元不是视口！");
            peo.AddAllowedClass(typeof(Viewport), true);
            PromptEntityResult per = ed.GetEntity(peo);
            if (per.Status != PromptStatus.OK)
                return;
            using (Transaction tr = db.TransactionManager.StartTransaction())
            {
                //获取当前空间的块表记录
                BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForRead);
                //获取当前空间中的当前布局
                Layout lay = (Layout)tr.GetObject(btr.LayoutId, OpenMode.ForRead);
                //布局名称
                ed.WriteMessage("\nLayoutName:" + lay.LayoutName);
                //布局ID
                ed.WriteMessage("\nId:" + lay.Id.ToString());
                ed.WriteMessage("\nObjectId:" + lay.ObjectId.ToString());
                ed.WriteMessage("\nbtr.LayoutId:" + btr.LayoutId);
                //当前空间ID
                ed.WriteMessage("\nCurrentSpaceId:" + lay.BlockTableRecordId.ToString());
                //通过选择集方式访问视口对象
                Viewport vp = (Viewport)tr.GetObject(per.ObjectId, OpenMode.ForRead);
                ed.WriteMessage("\nViewPort OwnerId:" + vp.OwnerId);
                ed.WriteMessage("\nLayout OwnerId:" + lay.OwnerId);
                ed.WriteMessage("\nbtr OwnerId:" + btr.OwnerId);
                
                //取得图纸空间中所有浮动视口对象
                Viewport Vports = (Viewport)tr.GetObject(db.PaperSpaceVportId, OpenMode.ForRead);
                foreach (ObjectId id in viewportIDs)
                {
                    //通过遍历视口ID方式访问视口对象
                    Viewport vp1 = id.GetObject(OpenMode.ForRead) as Viewport;
                }
                Matrix3d PsToMsTransForm = PaperToModel(vp);
                //取得当前图形中所有的BlockTable
                BlockTable bt = (BlockTable)db.BlockTableId.GetObject(OpenMode.ForRead);
                //取得当前图形中所有的BlockTable
                BlockTable bt_other = (BlockTable)tr.GetObject(db.BlockTableId, OpenMode.ForRead);
                //取得当前空间的所有块表记录
                BlockTableRecord btr_CurrentSpace = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForRead);
                ed.WriteMessage("\n" + btr_CurrentSpace.Name);
                //取得模型空间中所有的块表记录
                BlockTableRecord btr_model = (BlockTableRecord)bt["*Model_Space"].GetObject(OpenMode.ForRead);
                ed.WriteMessage("\n" + btr_model.Name);
                //取得图纸空间中所有的块表记录
                BlockTableRecord btr_paper = (BlockTableRecord)bt["*Paper_Space"].GetObject(OpenMode.ForRead);
                ed.WriteMessage("\n" + btr_paper.Name);
                //取得块名为TestBlock的记录
                BlockTableRecord btr_block = (BlockTableRecord)bt["TestBlock"].GetObject(OpenMode.ForRead);
                ed.WriteMessage("\n块名为：{0}，块属于{1}" , btr_block.Name,btr_block.OwnerId);
                tr.Commit();
            }
        }