如何打断曲线？

• 回答：

  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

  
  

  c#代码实现如下：

  
  

      private void DoSplitCurves()
      {
          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;
          }
  
          MxDrawPoint getPt1 = (MxDrawPoint)(mxUtility.GetPoint(null, "点取打断位置:"));        
          if (getPt1 == null)
          {
              MessageBox.Show("用户取消..");            
              return;
          }
          MxDrawResbuf param = new MxDrawResbuf();
          param.AddPoint(getPt1, -10);
  
          object objId;        
          if (curve.SplitCurves(param,out objId))
          {
              MxDrawResbuf rbId = (MxDrawResbuf)objId;
              MessageBox.Show("打断成功，生成的曲线个数:" + rbId.Count);            
              // 把以前的删除掉。
              ent.Erase();
          }        
          else
          {
              MessageBox.Show("打断失败");
          }
      }

  
  

  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();
           }