【每天一个demo】创建一个Employee 对象

本demo目标，准备创建一个圆，椭圆，多文本对象。这个代码比较难，我看了半天才算搞点清楚，还有点问题。用到了

using Autodesk.AutoCAD.Runtime ;using Autodesk.AutoCAD.DatabaseServices;using Autodesk.AutoCAD.Geometry;using Autodesk.AutoCAD.Colors;using Autodesk.AutoCAD.EditorInput;

包括事务处理（Transaction）、对象Id（ObjectId）、符号表（symbol tables，如块表BlockTable和层表LayerTable）以及对象引用。使用的其它一些对象如颜色Color、三维点Point3d和三维向量Vector3d，都和各自的步骤有关，但重点应该放在数据库基础上。

整体代码如下：

using System ;using Autodesk.AutoCAD.Runtime ;using Autodesk.AutoCAD.DatabaseServices;using Autodesk.AutoCAD.Geometry;using Autodesk.AutoCAD.Colors;using Autodesk.AutoCAD.EditorInput;[assembly:CommandClass(typeof(CsMgdAcad6.Class1))]namespace CsMgdAcad6{ public class Class1 { public Class1() { //析构函数 } public ObjectId CreateEmployeeDefinition() { ObjectId newBtrId = new ObjectId(); Database db = HostApplicationServices.WorkingDatabase; using (Transaction trans = db.TransactionManager.StartTransaction()) { BlockTable bt = (BlockTable)trans.GetObject(db.BlockTableId,OpenMode.ForWrite); if (bt.Has("EmployeeBlock")) { newBtrId =bt[ "EmployeeBlock"]; } else { Point3d center = new Point3d(10,20,30); Circle circle = new Circle(center, Vector3d.XAxis, 2); MText text = new MText(); text.Contents = "拉拉"; text.Location = center; Ellipse ellipse = new Ellipse(center, Vector3d.ZAxis, new Vector3d(3, 0, 0), 0.5, 0, 0); ObjectId empId = CreateLayer(); text.LayerId = empId; circle.LayerId = empId; ellipse.LayerId = empId; text.ColorIndex = 2; circle.ColorIndex = 3; BlockTableRecord newbtr = new BlockTableRecord(); newbtr.Name = "EmployeeBlock"; newBtrId = bt.Add(newbtr); trans.AddNewlyCreatedDBObject(newbtr, true); newbtr.AppendEntity(circle); newbtr.AppendEntity(text); newbtr.AppendEntity(ellipse); trans.AddNewlyCreatedDBObject(circle,true); trans.AddNewlyCreatedDBObject(text,true); trans.AddNewlyCreatedDBObject(ellipse,true); } trans.Commit(); } return newBtrId; } private ObjectId CreateLayer() { ObjectId layerId; Database db = HostApplicationServices.WorkingDatabase; using (Transaction trans = db.TransactionManager.StartTransaction()) { LayerTable lt = (LayerTable)trans.GetObject(db.LayerTableId, OpenMode.ForRead); if (lt.Has("EmployeeLayer")) { layerId = lt["EmployeeLayer"]; } else { LayerTableRecord ltr = new LayerTableRecord(); ltr.Name = "EmployeeLayer"; ltr.Color = Color.FromColorIndex(ColorMethod.ByAci, 2); lt.UpgradeOpen(); layerId = lt.Add(ltr); trans.AddNewlyCreatedDBObject(ltr, true); trans.Commit(); } } return layerId; } [CommandMethod("create")] public void createEmployee() { Database db = HostApplicationServices.WorkingDatabase; Editor ed = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.Editor; Transaction trans = db.TransactionManager.StartTransaction(); try { BlockTable bt = (BlockTable)(trans.GetObject(db.BlockTableId, OpenMode.ForWrite)); BlockTableRecord btr = (BlockTableRecord)trans.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite); BlockReference br = new BlockReference(new Point3d(10, 20, 30), CreateEmployeeDefinition()); } catch (System.Exception e) { ed.WriteMessage("有错误：" + e.Message); } finally { trans.Dispose(); } } }}

有没有人也是做cad二次开发 的，大家交流下，QQ：147395780，注：cad，谢谢