環(huán)境配置完了之后，現(xiàn)在開(kāi)始正式進(jìn)入開(kāi)發(fā)階段，此處使用一個(gè)示例，選擇圖紙中的一個(gè)Text，計(jì)算器OBB包圍盒，并顯示出來(lái)。
1.示例代碼

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ZwSoft.ZwCAD.ApplicationServices;
using ZwSoft.ZwCAD.DatabaseServices;
using ZwSoft.ZwCAD.EditorInput;
using ZwSoft.ZwCAD.Runtime;
using ZwSoft.ZwCAD.Geometry;

namespace ZWCADStartup
{
    public class CreateRectangleCommand
    {
        [CommandMethod("CR")]
        public void CreateRectangle()
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;
            Editor ed = doc.Editor;

            //選擇一個(gè)DBText
            var entOpts = new PromptEntityOptions("\n選擇Text對(duì)象: ");
            entOpts.SetRejectMessage("\n所選對(duì)象非Text類型.");
            entOpts.AddAllowedClass(typeof(DBText), true);
            var entRes = ed.GetEntity(entOpts);
            if (entRes.Status != PromptStatus.OK)
                return;

            using (Transaction tr = db.TransactionManager.StartTransaction())
            {
                // 提取DBText的轉(zhuǎn)換矩陣
                var text = (DBText)tr.GetObject(entRes.ObjectId, OpenMode.ForWrite);
                var plane = new Plane(Point3d.Origin, text.Normal);
                var xform =
                    Matrix3d.Rotation(text.Rotation, text.Normal, text.Position) *
                    Matrix3d.Displacement(text.Position.GetAsVector()) *
                    Matrix3d.PlaneToWorld(plane);

                // DBText逆向回原始位置
                text.TransformBy(xform.Inverse());

                // 計(jì)算DBText逆向后的包圍盒
                var extents = text.GeometricExtents;
                double minX = extents.MinPoint.X;
                double minY = extents.MinPoint.Y;
                double maxX = extents.MaxPoint.X;
                double maxY = extents.MaxPoint.Y;

                // 繪制包圍盒
                using (var pline = new Polyline())
                {
                    pline.AddVertexAt(0, new Point2d(minX, minY), 0.0, 0.0, 0.0);
                    pline.AddVertexAt(1, new Point2d(maxX, minY), 0.0, 0.0, 0.0);
                    pline.AddVertexAt(2, new Point2d(maxX, maxY), 0.0, 0.0, 0.0);
                    pline.AddVertexAt(3, new Point2d(minX, maxY), 0.0, 0.0, 0.0);
                    pline.Closed = true;
                    pline.Color = ZwSoft.ZwCAD.Colors.Color.FromRgb(255, 0, 0);

                    var space = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForWrite);
                    space.AppendEntity(pline);
                    tr.AddNewlyCreatedDBObject(pline, true);
                    //應(yīng)用DBText的轉(zhuǎn)換矩陣
                    pline.TransformBy(xform);
                }

                // 恢復(fù)DBText的位置
                text.TransformBy(xform);
                tr.Commit();
            }
        }
    }
}

2.測(cè)試
（1）F5執(zhí)行代碼
（2）進(jìn)入界面后，執(zhí)行NETLOAD，選擇加載生成的類庫(kù)文件。
（3）輸入CR命令，選擇一個(gè)DBText對(duì)象。（此處請(qǐng)先添加好）
（4）查看效果

Snipaste_2021-08-25_10-51-20.png