C#绘图(可以处理负值)[3]

    for(int i =0;i<num;i++)
    {
     PointF pfStart = new PointF();
     PointF pfEnd = new PointF();
     pfStart.X = orign.X;
     pfEnd.X = orign.X + width;
     pfStart.Y = orign.Y + i*height/5;
     pfEnd.Y = pfStart.Y;
     startPoint[i] = pfStart;
     endPoint[i] = pfEnd;
    }
    return startPoint;
   }
   public  int[] getZuoBiaoValue(int[] data,out int chidu)
   {
    int[] result = new Int32[11];
    int Max = data[0];
    
    for(int i=0;i<data.Length;i++)
    {
     if(Max < data[i])
      Max = data[i];
    }
    string strMax = Max + "";
    chidu =(int)((Convert.ToInt32(strMax.Substring(0,1)) +1)* Math.Pow(10,strMax.Length-1))/5;
    for(int i=0;i<result.Length;i++)
    {
     result[i] = chidu* (5-i) ;
    }
    return result;
   }
   
   #region get color
   public static Color GetChartItemColor(int itemIndex)
   {
    Color selectedColor;
    switch(itemIndex)
    {
     case 0:
      selectedColor = Color.Blue;
      break;
     case 1:
      selectedColor = Color.Red;
      break;
     case 2:
      selectedColor = Color.Yellow;
      break;
     case 3:
      selectedColor = Color.Purple;
      break;
     default:
      selectedColor = Color.Green;
      break;
    }
    return selectedColor;
   }
   #endregion
  }
 }