绘制曲线

private   void   Cal(System.Drawing   .Point     []   pt) { double   max=0.00,min=0.00; int   maxIdex=0,minIndex=0; System.Collections   .Hashtable     linePoint=new   Hashtable   ();//点集 System.Collections   .Hashtable     kPoint=new   Hashtable   ();//斜率 int   i=0; foreach(Point   tempt   in     pt) { linePoint[i]=tempt; i++; } /计算斜率 while   (i> 0) { Point   tempt1=(Point)linePoint[i-1]; Point   tempt2=(Point)linePoint[i]; kPoint[i]=(double)(tempt2.Y   -tempt1.Y   )/(tempt2.X     -tempt1.X); } 找出斜率最大和最小的值 foreach(DictionaryEntry     item   in   kPoint) { if(max <(double)item.Value   ) { max=(double)item.Value   ; maxIdex=(int)item.Key; } if(min> (double)item.Value   ) { min=(double)item.Value   ; minIndex=(int)item.Key; } }                         string   maxk=kPoint[maxIdex].ToString   ();//最大斜率 Point     maxBegin=(Point)linePoint[maxIdex-1];//最大斜率起点         Point     maxEnd=(Point)linePoint[maxIdex];//最大斜率终点         string   mink=kPoint[minIndex].ToString   ();//最小斜率 Point     minBegin=(Point)linePoint[minIndex-1];//最小斜率起点 Point     minEnd=(Point)linePoint[minIndex];//最大小斜率终点 }