如何实现自定义实体？

• 回答：

  参考例子 ：Src\MxDraw5.2\samples\ie\iedemoTest.htm

   

  1) 增加自定义实体对象

  调用DrawCustomEntity函数，绘制一个自定义实体对象

  函数说明如下:

   

  JS例子，下面代码绘制一个自定义实体，设置了两个属性，属性名分别” startpoint”,” endpoint”的两个点坐标，

   

  // 插入自定义实体函数

  function InsertCustomEntity() {

   

      var getPt = mxOcx.NewComObject("IMxDrawUiPrPoint");

      getPt.message = "点取第一点";

      if (getPt.go() != 1)

          return;

      var frstPt = getPt.value();

      if (frstPt == null)

          return;

   

      var getSecondPt = mxOcx.NewComObject("IMxDrawUiPrPoint");

   

      getSecondPt.message = "点取第二点";

      getSecondPt.basePoint = frstPt;

   

      getSecondPt.setUseBasePt(true);

   

   

      if (getSecondPt.go() != 1)

          return;

   

      var secondPt = getSecondPt.value();

      if (secondPt == null)

          return;

   

      var ent = mxOcx.DrawCustomEntity("TestMxCustomEntity", "");

   

   

      ent.SetPoint("spt", frstPt);

      ent.SetPoint("ept", secondPt);

  };

   

  2) 响应自定义事件，绘制自定义实体

  需要响应DMxDrawXEvents::CustomEntity_Explode事件

  帮助如下：

   

   

  JS例子，下面例子，得到自实体的数据，根据自定义实体的两个必属，开始点，和结束点绘制一个直线

        

  // 自定义实体绘制函数

  function ExplodeFun(pCustomEntity, pWorldDraw) {

   

   

      var sGuid = pCustomEntity.Guid;

      if (sGuid == "TestMxCustomEntity") {

          if (!pCustomEntity.IsHave("ept"))

              return;

   

          var stp = pCustomEntity.GetPoint("spt");

          if (stp == null)

              return;

   

          var ept = pCustomEntity.GetPoint("ept");

          if (ept == null)

              return;

   

          var mxUtility = mxOcx.NewUtility();

          var vec = ept.SumVector(stp);

   

          vec.Mult(0.5);

   

          var midPt = mxOcx.NewPoint();

   

          midPt.x = stp.x;

          midPt.y = stp.y;

          midPt.Add(vec);

   

          var dAng = vec.Angle();

          dAng = mxUtility.GetDimAngle(dAng);

   

          var dDis = 0.0;

          dDis = stp.DistanceTo(ept);

   

          var sTxt = "L=" + formatNumber(dDis, '#.##');

   

          dAng = dAng * 180.0 / 3.14159265;

   

          vec.RotateByXyPlan(3.14159265 / 2.0);

          vec.Normalize();

          vec.Mult(10);

   

          stp.Add(vec);

          ept.Add(vec);

   

          pWorldDraw.DrawLine(stp.x, stp.y, ept.x, ept.y);

   

          vec.Mult(2);

   

          stp.Sum(vec);

          ept.Sum(vec);

   

          pWorldDraw.DrawLine(stp.x, stp.y, ept.x, ept.y);

   

          pWorldDraw.SetColorIndex(1);

   

          pWorldDraw.DrawText(midPt.x, midPt.y, sTxt, 5, dAng,

  1, 2);

   

          mxOcx.SetEventRet(1);

   

      }

  }

  3) 响应自定义事件，返回自定义实体夹点

   

  需要响应_DMxDrawXEvents::CustomEntity_getGripPoints事件

  帮助如下：

   

  JS例子，返回自定义实体的开始夹点，和结束夹点。

  // 返回自定义实体夹点

  function GetGripPointsFun(pCustomEntity) {

   

      var sGuid = pCustomEntity.Guid;

      if (sGuid == "TestMxCustomEntity") {

          if (!pCustomEntity.IsHave("ept"))

              return;

   

          var stp = pCustomEntity.GetPoint("spt");

          if (stp == null)

              return;

   

          var ept = pCustomEntity.GetPoint("ept");

          if (ept == null)

              return;

   

          var ret = mxOcx.NewResbuf();

   

          ret.AddPoint(stp);

          ret.AddPoint(ept);

   

          mxOcx.SetEventRetEx(ret);

      }

  }

  4) 响应自定义事件，夹点移动后的处理

   

  需要响应CustomEntity_moveGripPointsAt事件

  帮助如下：

   

  JS例子，夹点移动后，修改自定义实体的属性

    // 移动自定义实体夹点

  function MoveGripPointsFun(pCustomEntity, lGridIndex, dOffsetX, dOffsetY) {

   

      var sGuid = pCustomEntity.Guid;

      if (sGuid == "TestMxCustomEntity") {

          if (!pCustomEntity.IsHave("ept"))

              return;

   

          var stp = pCustomEntity.GetPoint("spt");

          if (stp == null)

              return;

   

          var ept = pCustomEntity.GetPoint("ept");

          if (ept == null)

              return;

   

   

          if (lGridIndex == 0) {

              stp.x = stp.x + dOffsetX;

              stp.y = stp.y + dOffsetY;

              pCustomEntity.SetPoint("spt", stp);

          }

          else {

              ept.x = ept.x + dOffsetX;

              ept.y = ept.y + dOffsetY;

              pCustomEntity.SetPoint("ept", ept);

          }

   

          mxOcx.SetEventRet(1);

      }

  }