选择对象，输出块文件

• 回答：

         private void ToDWG()
          {
              MxDrawSelectionSet ss = new MxDrawSelectionSet();
              ss.Select(MCAD_McSelect.mcSelectionSetUserSelect, null, null, null);
  
              MxDrawResbuf param = new MxDrawResbuf();
  
              List<Int64> aryId = new List<Int64>();            for (Int32 i = 0; i < ss.Count; i++)
              {
                  MxDrawEntity ent = ss.Item(i);                if (ent != null)
                  {
                      param.AddObjectId(ent.ObjectID);
                      aryId.Add(ent.ObjectID);
                      ent.Close();
                  }
              }            //  计算新的图块的插入基点，把所实体外包的中点做为插入基点。
              MxDrawDatabase curDatabase = (MxDrawDatabase)axMxDrawX1.GetDatabase();            double dMinX = 0, dMinY = 0, dMaxX = 0, dMaxY = 0;            bool isFirstEnt = true;            for (int l = 0; l < aryId.Count; l++)
              {
                  MxDrawMcDbObject pObj = curDatabase.ObjectIdToObject(aryId[l]);                if (pObj == null)                    continue;
  
                  MxDrawEntity pEnt = (MxDrawEntity)pObj;                if (pEnt == null)                    continue;
  
  
                  MxDrawPoint pt1Ob, pt2Ob;
                  pEnt.GetBoundingBox(out pt1Ob, out pt2Ob);
  
                  MxDrawPoint minPt = (MxDrawPoint)pt1Ob;
                  MxDrawPoint maxPt = (MxDrawPoint)pt2Ob;                if (minPt != null && maxPt != null)
                  {                    if(isFirstEnt)
                      {
                          dMinX = minPt.x;
                          dMinY = minPt.y;
                          dMaxX = maxPt.x;
                          dMaxY = maxPt.y;
                          isFirstEnt = false;
                      }                    else
                      {                        if (dMinX > minPt.x)
                              dMinX = minPt.x;                        if (dMinY > minPt.y)
                              dMinY = minPt.y;                        if (dMaxX < maxPt.x)
                              dMaxX = maxPt.x;                        if (dMaxY < maxPt.y)
                              dMaxY = maxPt.y;
                      }
                  }   
              }            if(isFirstEnt)
              {                // 没有实体
                  return;
              }
  
              MxDrawPoint pos = new MxDrawPoint();
              pos.x = dMinX + (dMaxX - dMinX) / 2.0;
              pos.y = dMinY + (dMaxY - dMinY) / 2.0;            //
              MxDrawIdMapping idMap;
      
              MxDrawDatabase newDatabase = curDatabase.Wblock(param,pos,out idMap);            if(newDatabase == null)                return;            // 保存为dwg文件。
              if (newDatabase.SaveAs("G:\wblock.dwg", 1, null))
              {
                  MessageBox.Show("Ok");
              }            else
              {
                  MessageBox.Show("Failed");
              }
          }