CAD选择曲线，把曲线从中间1/4 到 3/ 4处断开(com接口c#语言)

主要用到函数说明：

IMxDrawCurve::SplitCurves

打断曲线，详细说明如下：

参数	说明
[in] IMxDrawResbuf* aryParam	打断位置参数数组,或打断的点数组,是个MxDrawResbuf对象
[out] IMxDrawResbuf** aryNewId	返回打断后生成的新曲线id，是个MxDrawResbuf对象

 选择曲线，把曲线从中间1/4 到 3/ 4处断开：

           MxDrawUtility mxUtility = new MxDrawUtility();

         object getPt;

         MxDrawEntity ent = mxUtility.GetEntity(out getPt, "选择打断的曲线:");         

         if (ent == null)             

             return;

 

         MxDrawCurve curve;         

         if (ent is MxDrawCurve)

         {

             curve = (MxDrawCurve)ent;

         }         

         else

         {

             MessageBox.Show("实体类型不对");             

             return;

         }         

         double dLen = 0.0;

         curve.GetDistAtParam(curve.GetEndParam(),out dLen);

 

         object pt1;         

         if (!curve.GetPointAtDist(dLen / 4.0, out pt1))             

         return;

  

         object pt2;         

         if (!curve.GetPointAtDist(dLen * 3.0 / 4.0, out pt2))             

         return;

 

         MxDrawPoint breakPt1 = (MxDrawPoint)pt1;

         MxDrawPoint breakPt2 = (MxDrawPoint)pt2;         

         if (breakPt1 == null || breakPt2 == null)             

         return;

 

         MxDrawResbuf param = new MxDrawResbuf();

         param.AddPoint(breakPt1, -10);

         param.AddPoint(breakPt2, -10);

 

         object objIds;         

         if (curve.SplitCurves(param, out objIds))

         {

             MxDrawResbuf rbId = (MxDrawResbuf)objIds;             

             if(rbId.Count == 3)

             {

                 axMxDrawX1.Erase(rbId.AtLong(1));

             }             

             // 把以前的删除掉。

             ent.Erase();

         }