模拟向命令窗口发送全图居中的命令：  Application.DocumentManager.MdiActiveDocument.SendStringToExecute("z\ne\n",true,false,false); 

弹窗命令：

 Application.ShowAlertDialog("Erase the newly added polyline.");

本例在cad画一条线并全图显示：

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ClassLibrary4
{
    public class Class1
    {
        [CommandMethod("xx")]
        public static void AngleFromXAxis()
        {
            //
            
            // 获得当前文档和数据库   Get the current document and database
            Document acDoc = Application.DocumentManager.MdiActiveDocument;
            Database acCurDb = acDoc.Database;

            // 启动一个事务  Start a transaction
            using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
            {
                // 以只读方式打开块表   Open the Block table for read
                BlockTable acBlkTbl;
                acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,
                                             OpenMode.ForRead) as BlockTable;

                // 以写方式打开模型空间块表记录   Open the Block table record Model space for write
                BlockTableRecord acBlkTblRec;
                acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
                                                OpenMode.ForWrite) as BlockTableRecord;

                // 创建一条轻量多段线     Create a lightweight polyline
                Polyline acPoly = new Polyline();
                acPoly.SetDatabaseDefaults();
                acPoly.AddVertexAt(0, new Point2d(2, 4), 0, 0, 0);
                acPoly.AddVertexAt(1, new Point2d(4, 2), 0, 0, 0);
                acPoly.AddVertexAt(2, new Point2d(6, 4), 0, 0, 0);

                // 添加新对象到块表记录和事务中   Add the new object to the block table record and the transaction
                acBlkTblRec.AppendEntity(acPoly);
                acTrans.AddNewlyCreatedDBObject(acPoly, true);

                // 更新显示并显示一条提醒消息    Update the display and display an alert message
                acDoc.Editor.Regen();
                //acDoc.Editor.WriteMessage("z\n");
                //acDoc.Editor.Regen();
                //acDoc.Editor.WriteMessage("e\n");
                Application.DocumentManager.MdiActiveDocument.SendStringToExecute("z\ne\n",true,false,false); 
                acDoc.Editor.Regen();
                Application.DocumentManager.MdiActiveDocument.SendStringToExecute("regen", true, false, false);
                Application.ShowAlertDialog("pl线已画好");

                // 从图形中删除多段线    Erase the polyline from the drawing
                //acPoly.Erase(true);
               // Application.ShowAlertDialog("pl线已删除");
                // 保存新对象到数据库中   Save the new object to the database
                acTrans.Commit();
            }


            //
            
            //


        }
    }
}