036集——显示图元所有属性信息、输出块定义中所有实体信息（CAD—C#二次开发入门）

输出块定义中所有实体信息

如图，通过选择块参照找到对应的块定义，输出块定义所有图元所有属性信息到桌面txt文档。

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using System;
using System.IO;
using Path = System.IO.Path;

namespace CadBlockExport命名空间可以修改吗
{
    public class Commands
    {
        [CommandMethod("xx")]
        public static void 块demo()
        {
            // 获取当前文档和数据库
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Database db = doc.Database;
            Editor ed = doc.Editor;
            // 提示用户选择块参照
            PromptEntityOptions peo = new PromptEntityOptions("\n选择一个块参照: ");
            peo.SetRejectMessage("\n选择的对象不是块参照，请重新选择。");
            peo.AddAllowedClass(typeof(BlockReference), true);

            PromptEntityResult per = ed.GetEntity(peo);
            if (per.Status != PromptStatus.OK) return;

            using (Transaction tr = db.TransactionManager.StartTransaction())
            {
                // 打开所选的块参照
                BlockReference blockRef = tr.GetObject(per.ObjectId, OpenMode.ForRead) as BlockReference;
                if (blockRef == null)
                {
                    ed.WriteMessage("\n所选对象不是有效的块参照。");
                    tr.Commit();
                    return;
                }

                // 获取块定义
                BlockTableRecord blockDef = tr.GetObject(blockRef.BlockTableRecord, OpenMode.ForRead) as BlockTableRecord;
                if (blockDef == null)
                {
                    ed.WriteMessage("\n无法获取块定义。");
                    tr.Commit();
                    return;
                }

                // 获取桌面路径
                string desktopPath = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
                string baseFileName = "BlockInfo.txt";
                string filePath = Path.Combine(desktopPath, baseFileName);
                int copyCount = 1;

                // 检查文件是否存在，如果存在则添加 "副本" 字样
                while (File.Exists(filePath))
                {
                    string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(baseFileName);
                    string extension = Path.GetExtension(baseFileName);
                    filePath = Path.Combine(desktopPath, $"{fileNameWithoutExtension} 副本{copyCount}{extension}");
                    copyCount++;
                }

                try
                {
                    // 打开文件进行写入
                    using (StreamWriter sw = new StreamWriter(filePath))
                    {
                        // 写入块参照的位置
                        sw.WriteLine($"块参照位置: {blockRef.Position}");