关于偏移GetOffset的使用方法，点哪边则偏移哪边（偏移方向）！

jiikoo · 发表于 2014-6-1 15:33:00

using System;
using Autodesk..DatabaseServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
[assembly: CommandClass(typeof(qian2014531.qian2014531a))]
namespace qian2014531
{
class qian2014531a
{
      [CommandMethod("sf")]
      public void qianpp()
      {
         Document doc = Application.DocumentManager.MdiActiveDocument;
         Database db = doc.Database;
         Editor ed = doc.Editor;
         PromptEntityResult ent = ed.GetEntity("选择实体");
         Entity entity = null;
         using (Transaction transaction = db.TransactionManager.StartTransaction())
         {
            entity = (Entity)transaction.GetObject(ent.ObjectId, OpenMode.ForRead, true);
            transaction.Commit();
         }
         // 拾取点，指定偏移的方向“点 ”
         PromptPointResult pPtRes;
         PromptPointOptions pPtOpts = new PromptPointOptions("");
         pPtOpts.Message = "\nEnter the start point of the line: ";
         pPtRes = doc.Editor.GetPoint(pPtOpts);
         Point3d DirectOffsetPt = pPtRes.Value;
         double offsetDist = 10;
         Curve mycurve = entity as Curve;
         Point3d offPtNew = new Point3d(DirectOffsetPt.X, DirectOffsetPt.Y, 0);
      //这里开始判断偏移的方向
         Point3d pt1 = mycurve.GetClosestPointTo(offPtNew, false);
         pt1 = new Point3d(pt1.X, pt1.Y, 0);
         Vector3d vec1 = offPtNew - pt1;
         Vector3d vec2 = mycurve.GetFirstDerivative(pt1);
         Vector3d vec3 = vec1.CrossProduct(vec2);
         if (vec3.Z < 0)
         {
            offsetDist = -offsetDist;
         }
         if (mycurve.GetType() == typeof(Line))
         {
            offsetDist = -offsetDist;
         }
      //结束，这里开始判断偏移的方向          using (Transaction acTrans = db.TransactionManager.StartTransaction())
{
         // 以读模式打开Block 表
         BlockTable acBlkTbl;
         acBlkTbl = acTrans.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
         // 以写模式打开块表记录模型空间
         BlockTableRecord acBlkTblRec;
         acBlkTblRec =acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],OpenMode.ForWrite) as BlockTableRecord;
         DBObjectCollection objCol = new DBObjectCollection();
         objCol = mycurve.GetOffsetCurves(offsetDist);
         // 遍历得到的新对象
         foreach (Curve acEnt in objCol)
         {
            // 添加每个对象
            acBlkTblRec.AppendEntity(acEnt);
            acTrans.AddNewlyCreatedDBObject(acEnt, true);
         }
         acTrans.Commit();
}
      }
}
}