来自 SQL 数据源的图表，但日期时间为刻度

Question

我有一个 SQL 数据库，其中存储了一些我想绘制图表的数据。问题是，我继承了这个数据库，他们将日期时间值存储为 Ticks。当我将图表数据源设置为此表时，它似乎不理解刻度。

如何让我的图表将刻度转换回我的图表可以理解的 DateTime 格式？

数据库表

我的 SQL 查询和代码：

static public DataTable get_I1(RunningTests rt)
{
    DataTable dt = new DataTable();

    using (SqlConnection cs = new SqlConnection(connString))
    {
        string query = string.Format("SELECT Time_Stamp, I1 FROM Test WHERE Unit_ID = '{0}' AND Time_Stamp >= '{1}' AND Time_Stamp <= '{2}'", rt.Unit_ID, rt.StartTime.Ticks, rt.StopTime.Ticks);
        Console.WriteLine(query);
        SqlCommand cmd = new SqlCommand(query, cs);

        using (SqlDataAdapter da = new SqlDataAdapter(cmd))
        {
            da.Fill(dt);
        }
    }

    dt.DefaultView.Sort = "Time_Stamp DESC";
    dt = dt.DefaultView.ToTable();

    return dt;
}

设置图表数据源的代码：

private void do_chart_I1(RunningTests rt)
{
    muCalGUI1.chartI1.Series.Clear();

    DataTable dt = SQL.get_I1(rt);

    muCalGUI1.chartI1.DataSource = dt;

    Series s = new Series("I1");
    s.XValueMember = "Time_Stamp";
    s.YValueMembers = "I1";
    s.ChartType = SeriesChartType.Line;
    s.BorderWidth = 2;
    s.MarkerSize = 5;
    s.MarkerStyle = MarkerStyle.Circle;

    muCalGUI1.chartI1.ChartAreas[0].AxisY.IsStartedFromZero = false;
    muCalGUI1.chartI1.ChartAreas[0].AxisX.LabelStyle.Format = "yyyy-MM-dd\nHH:mm:ss";
    muCalGUI1.chartI1.ChartAreas[0].AxisY.LabelStyle.Format = "0";
    muCalGUI1.chartI1.ChartAreas[0].RecalculateAxesScale();

    muCalGUI1.chartI1.Series.Add(s);
    muCalGUI1.chartI1.Legends.Clear();
}

结果：

期望的结果：

Answer 1

我有一个可行的解决方案。如果有人可以提供“更干净”的方法，我很乐意将其标记为答案。目前我的工作是创建一个新的数据表并将刻度转换为日期时间。

SQL 代码：

static public DataTable get_I1(RunningTests rt)
{
    DataTable dt = new DataTable();

    using (SqlConnection cs = new SqlConnection(connString))
    {
        //string query = string.Format("Select TOP {0} Serial AS [Serial #], Start, [Stop], N, ROUND(Mean,4) AS Mean, ROUND(StdDev,4) AS [Standard Deviation], ROUND(Minimum,4) AS Min, ROUND(Maximum,4) AS Max FROM TestTime JOIN Membrane ON TestTime.Membrane_ID = Membrane.Membrane_ID WHERE Serial LIKE '{1}' ORDER BY TestTime_ID", numRecords, serial);
        string query = string.Format("SELECT Time_Stamp, I1 FROM Test WHERE Unit_ID = '{0}' AND Time_Stamp >= '{1}' AND Time_Stamp <= '{2}'", rt.Unit_ID, rt.StartTime.Ticks, rt.StopTime.Ticks);
        SqlCommand cmd = new SqlCommand(query, cs);

        using (SqlDataAdapter da = new SqlDataAdapter(cmd))
        {
            da.Fill(dt);
        }
    }

    //Previous user stored the date time as ticks, have to convert back to DateTime
    DataTable dtCloned = new DataTable();
    dtCloned.Clear();
    dtCloned.Columns.Add("Time_Stamp", typeof(DateTime));
    dtCloned.Columns.Add("I1", typeof(int));

    foreach (DataRow dr in dt.Rows)
    {
        DataRow r = dtCloned.NewRow();
        r[0] = new DateTime((long)dr[0]);
        r[1] = dr[1];

        dtCloned.Rows.Add(r);
    }

    dtCloned.DefaultView.Sort = "Time_Stamp DESC";
    dtCloned = dtCloned.DefaultView.ToTable();

    return dtCloned;
}