C# 计算传入的时间距离今天的时间差

/// <summary>/// 计算传入的时间距离今天的时间差/// </summary>/// <param name="dt"></param>/// <param name="yy"></param>/// <param name="mm"></param>/// <param name="dd"></param>public void GetCriminalYX(DateTime dt, out int yy, out int mm, out int dd){DateTime now = DateTime.Now;yy = mm = dd = 0;if (dt.Year > 9000 || dt.Year == 1900){return;}if (dt <= now){return;}StringBuilder str = new StringBuilder();int dt_Y = dt.Year;int dt_M = dt.Month;int dt_D = dt.Day;int now_Y = DateTime.Now.Year;int now_M = DateTime.Now.Month;int now_D = DateTime.Now.Day;yy = dt_Y - now_Y;mm = dt_M - now_M;dd = 0;int dt_M_SY = 0;if (dt_D < now_D){mm -= 1;dt_M_SY = dt_M - 1;if (dt_M_SY == 0){dt_M_SY = 12;}if (dt_M_SY == 2){dt_M_SY = dt_Y % 4 == 0 ? 29 : 28;}else{dt_M_SY = dt_M_SY == 2 || dt_M_SY == 4 || dt_M_SY == 6 || dt_M_SY == 9 || dt_M_SY == 11 ? 30 : 31;}dt_D += dt_M_SY;}dd = dt_D - now_D;if (mm < 0){yy -= 1;mm += 12;}}