/// <summary>
/// 生成折线图报表图片
/// </summary>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="bottomStr"></param>
/// <param name="isDrowXline">是否划竖线刻度</param>
/// <returns></returns>
public byte[] BuildTrendPic(int width, int height,string bottomStr,bool isDrowXline=false)
/// <summary>
/// 求数组中的最大数 除以5后的数 用于y轴间隔
/// </summary>
/// <param name="tempArray"></param>
/// <returns>最大值，最小值，平均值</returns>
private List<int> ySpanAvg(List<float> tempArray)
