如何实现自定义实体？

• 回答：

  调用DrawCustomEntity函数，绘制一个自定义实体对象。

  
  

  下面代码绘制一个自定义实体，C#代码实现如下：

  
  

  private void DrawMlineCommand()
  {
      MxDrawUiPrPoint getPt = new MxDrawUiPrPoint();
      getPt.message = "点取第一点";
      if (getPt.go() != MCAD_McUiPrStatus.mcOk)
      {
          return;
      }
              
      var frstPt = getPt.value();
      if (frstPt == null)
      {
          return;
      }
   
      MxDrawUiPrPoint getSecondPt = new MxDrawUiPrPoint();
   
      getSecondPt.message = "点取第二点";
      getSecondPt.basePoint = frstPt;
   
      getSecondPt.setUseBasePt(false);
   
      MxDrawCustomEntity spDrawData = getSecondPt.InitUserDraw("DrawCustEntity");
      spDrawData.SetDouble("Width", 30);
   
      spDrawData.SetPoint("Point1", frstPt);
   
      Int32 lCount = 1;
      spDrawData.SetLong("Count", 1);
              
      while (true)
      {
          if (getSecondPt.go() != MCAD_McUiPrStatus.mcOk)
              break;
   
          var secondPt = getSecondPt.value();
          if (secondPt == null)
              break;
   
          lCount++;
   
          String sPointName = "Point" + lCount.ToString();
   
          spDrawData.SetPoint(sPointName, secondPt);
          spDrawData.SetLong("Count", lCount);
      }
      if (lCount > 1)
          axMxDrawX1.DrawEntity(spDrawData);
  }

  
  

  需要响应DMxDrawXEvents::CustomEntity_Explode事件。

  
  

  下面例子，得到自实体的数据，C#代码实现如下：

  
  

  private void axMxDrawX1_CustomEntity_Explode(object sender, AxMxDrawXLib._DMxDrawXEvents_CustomEntity_ExplodeEvent e)
          {
              MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pCustomEntity;
              var sGuid = pCustomEntity.Guid;
   
              MxDrawWorldDraw pWorldDraw = (MxDrawWorldDraw)e.pDraw;
   
              if (sGuid == "DrawCustEntity")
              {
                  MyDrawMline(pWorldDraw, pCustomEntity, null);
                  e.pRet = 1;
              }
          }
   
  private void MyDrawMline(MxDrawWorldDraw pWorldDraw, MxDrawCustomEntity pCustomEntity, MxDrawPoint curPt)
  {
      // 取自定义实体的端点数目，属性。
      if (!pCustomEntity.IsHave("Count"))
          return;
      long lCount = pCustomEntity.GetLong("Count");
      MxDrawPolyline tmpPl = new MxDrawPolyline();
      for (long i = 0; i < lCount; i++)
      {
          String sName;
          sName = "Point" + (i + 1).ToString();
          if (!pCustomEntity.IsHave(sName))
              break;
   
          // 取自定义实体的端点坐标。
          MxDrawPoint pt = pCustomEntity.GetPoint(sName);
   
          // 把端点坐标，传给pl线，用于生成双线。
          tmpPl.AddVertexAt(pt);
      }
      if (curPt != null)
          tmpPl.AddVertexAt(curPt);
   
      if (tmpPl.NumVerts < 2)
      {
          // 端点数少于2就，不构成直线，就不需要显示。
          return;
      }
      // 求pl线，开始点的导数.
      MxDrawVector3d vecFx;
      if (!tmpPl.GetFirstDeriv(tmpPl.GetStartParam(), out vecFx))
          return;
      if (vecFx.IsZeroLength())
          return;
      // 把向量旋转90度.
      vecFx.RotateByXyPlan(3.14159265 / 2.0);
      vecFx.Normalize();
      //  得到双线的宽度属性。
      double dWidth = pCustomEntity.GetDouble("Width");
      vecFx.Mult(dWidth);
      MxDrawPoint startPt = tmpPl.GetStartPoint();
   
      // 向pl线，两个方向偏移，
      MxDrawPoint offsetPt1 = new MxDrawPoint();
      offsetPt1.x = startPt.x;
      offsetPt1.y = startPt.y;
      offsetPt1.Add(vecFx);
      MxDrawPoint offsetPt2 = new MxDrawPoint();
      offsetPt2.x = startPt.x;
      offsetPt2.y = startPt.y;
      offsetPt2.Sum(vecFx);
      MxDrawText text = new MxDrawText();
      text.TextString = "Test";
      text.Height = 100;
      text.Position = startPt;
      text.AlignmentPoint = startPt;
      MxDrawPoint pt1, pt2;
      text.GetBoundingBox(out pt1, out pt2);
      MxDrawPoint pt3 = new MxDrawPoint();
      pt3.x = pt1.x;
      pt3.y = pt2.y;
      MxDrawPoint pt4 = new MxDrawPoint();
      pt4.x = pt2.x;
      pt4.y = pt1.y;
      MxDrawPoints pts = new MxDrawPoints();
      pts.Add(pt1.x, pt1.y, 0);
      pts.Add(pt3.x, pt3.y, 0);
      pts.Add(pt2.x, pt2.y, 0);
      pts.Add(pt4.x, pt4.y, 0);
   
      Int32 lDraworder = pWorldDraw.Draworder;
      pWorldDraw.Draworder = lDraworder + 1;
      pWorldDraw.DrawWipeout(pts);
      pWorldDraw.Draworder = lDraworder + 2;
      pWorldDraw.DrawEntity((MxDrawEntity)text);
      pWorldDraw.Draworder = lDraworder;
      //    pWorldDraw->
      {
          MxDrawResbuf newobj;
          if (tmpPl.OffsetCurves(dWidth, offsetPt1, out newobj))
          {
              for (Int32 j = 0; j < newobj.Count; j++)
              {
                  MxDrawEntity tmpObj = (MxDrawEntity)newobj.AtObject(j);
                  if (tmpObj == null)
                      continue;
   
                  pWorldDraw.DrawEntity(tmpObj);
              }
              newobj.RemoveAll();
          }
      }
      {
          MxDrawResbuf newobj;
          if (tmpPl.OffsetCurves(dWidth, offsetPt2, out newobj))
          {
              for (Int32 j = 0; j < newobj.Count; j++)
              {
                  MxDrawEntity tmpObj = (MxDrawEntity)newobj.AtObject(j);
                  if (tmpObj == null)
                      continue;
   
                  pWorldDraw.DrawEntity(tmpObj);
              }
              // 这不使用newobj，需要显示调用RemoveAll函数清楚内存。
              // 不然这个可能就会程序退出时才释放，这时它会去释放控件对象指针，有可能会出错。
              newobj.RemoveAll();
          }
      }
  }

  
  

  C#代码实现如下：

  
  

  private void axMxDrawX1_DynWorldDraw(object sender, AxMxDrawXLib._DMxDrawXEvents_DynWorldDrawEvent e)
  {
      MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pData;
      String sGuid = pCustomEntity.Guid;
      e.pRet = 0;
   
      MxDrawWorldDraw pWorldDraw = (MxDrawWorldDraw)e.pWorldDraw;
      MxDrawPoint curPt = new MxDrawPoint();
      curPt.x = e.dX;
      curPt.y = e.dY;
   
      if (sGuid == "DrawCustEntity")
      {
          MyDrawMline(pWorldDraw, pCustomEntity, curPt);
      }
  }

  
  

  需要响应_DMxDrawXEvents::CustomEntity_getGripPoints事件，C#代码实现如下：

  
  

  private void axMxDrawX1_CustomEntity_getGripPoints(object sender, AxMxDrawXLib._DMxDrawXEvents_CustomEntity_getGripPointsEvent e)
  {
      MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pCustomEntity;
      var sGuid = pCustomEntity.Guid;
      e.pOk = 0;
      if (sGuid == "DrawCustEntity")
      {
          if (!pCustomEntity.IsHave("Count"))
              return;
   
          long lCount = pCustomEntity.GetLong("Count");
   
          MxDrawResbuf ret = (MxDrawResbuf)axMxDrawX1.NewResbuf();
   
          for (long i = 0; i < lCount; i++)
          {
              String sName;
              sName = "Point" + (i + 1).ToString();
              if (!pCustomEntity.IsHave(sName))
                  break;
   
              // 取自定义实体的端点坐标。
              MxDrawPoint pt = pCustomEntity.GetPoint(sName);
   
   
              ret.AddPoint(pt);
          }
          e.pOk = 1;
          axMxDrawX1.SetEventRetEx(ret);
      }
   
  }

  
  

  需要响应CustomEntity_moveGripPointsAt事件。

  
  

  下面例子，夹点移动后，修改自定义实体的属性，C#代码实现如下：

  
  

  private void axMxDrawX1_CustomEntity_moveGripPointsAt(object sender, AxMxDrawXLib._DMxDrawXEvents_CustomEntity_moveGripPointsAtEvent e)
  {
      e.pRet = 1;
      MxDrawCustomEntity pCustomEntity = (MxDrawCustomEntity)e.pCustomEntity;
      var sGuid = pCustomEntity.Guid;
   
      if (sGuid == "DrawCustEntity")
      {
          if (!pCustomEntity.IsHave("Count"))
              return;
   
          long lCount = pCustomEntity.GetLong("Count");
                  
          for (long i = 0; i < lCount; i++)
          {
              String sName;
              sName = "Point" + (i + 1).ToString();
              if (!pCustomEntity.IsHave(sName))
                  break;
   
              // 取自定义实体的端点坐标。
              MxDrawPoint pt = pCustomEntity.GetPoint(sName);
   
              if (i == e.lGridIndex)
              {
                  pt.x = pt.x + e.dOffsetX;
                  pt.y = pt.y + e.dOffsetY;
   
                  pCustomEntity.SetPoint(sName, pt);
              }
          }
      }
  }