C# AutoCAD2010选择dwg中的一个块，获取其位置后，再在电脑本地选择一个外部块，在该位置去替换它，完整代码

好的，以下是完整代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
using System.IO;

namespace ReplaceBlock
{
    public class Commands
    {
        [CommandMethod("RB")]
        public void ReplaceBlock()
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Editor ed = doc.Editor;

            // 选择第一个块
            PromptEntityOptions peo1 = new PromptEntityOptions("\n选择第一个块: ");
            peo1.SetRejectMessage("\n必须选择块对象.");
            peo1.AddAllowedClass(typeof(BlockReference), true);
            PromptEntityResult per1 = ed.GetEntity(peo1);
            if (per1.Status != PromptStatus.OK)
            {
                ed.WriteMessage("\n无效的选择.");
                return;
            }

            // 获取第一个块的位置
            Transaction tr1 = doc.TransactionManager.StartTransaction();
            using (tr1)
            {
                BlockReference br1 = tr1.GetObject(per1.ObjectId, OpenMode.ForRead) as BlockReference;
                if (br1 != null)
                {
                    Point3d pt1 = br1.Position;

                    // 选择外部块文件
                    PromptOpenFileOptions pfo = new PromptOpenFileOptions("\n选择要插入的块文件: ");
                    pfo.Filter = "AutoCAD 块文件 (*.dwg)|*.dwg";
                    PromptFileNameResult pfnr = ed.GetFileNameForOpen(pfo);
                    if (pfnr.Status != PromptStatus.OK)
                    {
                        ed.WriteMessage("\n必须选择有效的块文件.");
                        return;
                    }

                    // 加载块文件并获取块定义
                    Database db2 = new Database(false, true);
                    using (db2)
                    {
                        db2.ReadDwgFile(pfnr.StringResult, FileOpenMode.OpenForReadAndAllShare, false, null);
                        ObjectIdCollection ids = new ObjectIdCollection();
                        foreach (ObjectId id in db2.BlockTableId)
                        {
                            ids.Add(id);
                        }
                        PromptEntityOptions peo2 = new PromptEntityOptions("\n选择要插入的块: ");
                        peo2.SetRejectMessage("\n必须选择块对象.");
                        peo2.AddAllowedClass(typeof(BlockReference), true);
                        peo2.AddAllowedClass(typeof(BlockTableRecord), true);
                        peo2.AddAllowedClass(typeof(DynamicBlockReference), true);
                        PromptEntityResult per2 = ed.GetEntity(peo2);
                        if (per2.Status != PromptStatus.OK)
                        {
                            ed.WriteMessage("\n无效的选择.");
                            return;
                        }
                        Entity ent2 = tr1.GetObject(per2.ObjectId, OpenMode.ForRead) as Entity;
                        if (ent2 is BlockTableRecord)
                        {
                            BlockTableRecord btr2 = ent2 as BlockTableRecord;
                            foreach (ObjectId id in btr2)
                            {
                                ids.Add(id);
                            }
                        }
                        else if (ent2 is BlockReference)
                        {
                            BlockReference br2 = ent2 as BlockReference;
                            ids.Add(br2.BlockTableRecord);
                        }

                        // 引用块并插入到块表记录中
                        BlockTableRecord btr = (BlockTableRecord)tr1.GetObject(br1.BlockTableRecord, OpenMode.ForWrite);
                        BlockTable bt = (BlockTable)tr1.GetObject(btr.Database.BlockTableId, OpenMode.ForRead);
                        ObjectId idBtr = ObjectId.Null;
                        foreach (ObjectId id in ids)
                        {
                            if (bt.Has(id))
                            {
                                BlockTableRecord btr2 = (BlockTableRecord)tr1.GetObject(id, OpenMode.ForRead);
                                if (!btr2.IsLayout && !btr2.IsAnonymous)
                                {
                                    idBtr = id;
                                    break;
                                }
                            }
                        }
                        if (idBtr.IsNull)
                        {
                            ed.WriteMessage("\n无法找到有效的块.");
                            return;
                        }
                        BlockReference br = new BlockReference(pt1, idBtr);
                        btr.AppendEntity(br);
                        tr1.AddNewlyCreatedDBObject(br, true);

                        // 复制块属性
                        BlockTableRecord btrSrc = (BlockTableRecord)tr1.GetObject(idBtr, OpenMode.ForRead);
                        BlockTableRecord btrDest = (BlockTableRecord)tr1.GetObject(br.BlockTableRecord, OpenMode.ForWrite);
                        foreach (ObjectId id in btrSrc)
                        {
                            Entity ent = tr1.GetObject(id, OpenMode.ForRead) as Entity;
                            if (ent != null)
                            {
                                Entity entCopy = ent.Clone() as Entity;
                                if (entCopy != null)
                                {
                                    btrDest.AppendEntity(entCopy);
                                    tr1.AddNewlyCreatedDBObject(entCopy, true);
                                }
                            }
                        }

                        // 删除第一个块
                        br1.Erase();
                    }
                }
                tr1.Commit();
            }
        }
    }
}

请注意，此代码仅适用于 AutoCAD 2010 并使用 C# 语言。使用时请将其编译为 .dll 文件并加载到 AutoCAD 中。在命令行中输入“RB”即可执行命令。