Microsoft Chart堆积柱形图有间隙

我正在使用 .Net 4.0 中的图表库来创建包含多个系列的堆叠柱形图。我的目标是一个直方图，显示多个系列（教师）每天的累积操作数（报告完成情况）。经常会丢失数据（特定教师当天没有活动）。

当系列中缺少数据时，我会在条形图中出现间隙：

My code:

    public ActionResult CompletionHistogram(int sid, int width, int height)
    {
        Site site = SiteRepository.Get(sid);
        if (site == null)
            return new HttpNotFoundResult();

        Chart chart = new Chart();
        chart.Height = height;
        chart.Width = width;
        ChartArea area = chart.ChartAreas.Add("Default");

        // Treat each teacher as a series
        foreach (Teacher t in site.Teachers)
        {
            Series series = chart.Series.Add(t.FullName);
            series.ChartType = SeriesChartType.StackedColumn;
            series.Name = t.FullName;

            // Group completions by day (filter out incomplete reports and null timestamps)
            var groups = t.StudentReports
                .Where<StudentReport>(rep => rep.IsComplete && rep.FirstSaveTimestamp.HasValue)
                .GroupBy<StudentReport, DateTime>(rep => rep.FirstSaveTimestamp.Value.Date);

            bool hasPoints = false;
            foreach (var g in groups)
            {
                series.Points.AddXY(g.Key, g.Count());
                hasPoints = true;
            }

            series.IsValueShownAsLabel = true;
            series.ToolTip = "#VALX";

            if (hasPoints)
                chart.DataManipulator.InsertEmptyPoints(1, IntervalType.Days, series);
        }


        area.AxisX.LabelStyle.Format = "ddd M/d";
        return new ChartResult(chart);
    }

我怎样才能删除

我有办法让这个工作成功。
很抱歉回答很长，但我发现您尝试实现此答案的方式会影响它是否有效。

添加点时，您需要手动将点设置为零。 注意：我无法通过事后添加零点来完成这项工作。

请参阅下面的示例和生成的屏幕截图： Chart1.Series.Clear(); Chart1.Series.Add(新系列()); Chart1.Series.Add(新系列()); Chart1.Series.Add(新系列()); Chart1.Series.Add(新系列());

foreach (Series s in chart1.Series)
{
    s.ChartType = SeriesChartType.StackedColumn;
}

//chart1.Series[0].Points.Add(new DataPoint(0, 0));
chart1.Series[0].Points.Add(new DataPoint(1, 3));
chart1.Series[0].Points.Add(new DataPoint(2, 3));
chart1.Series[0].Points.Add(new DataPoint(3, 3));

chart1.Series[1].Points.Add(new DataPoint(0, 3));
//chart1.Series[1].Points.Add(new DataPoint(1, 0));
chart1.Series[1].Points.Add(new DataPoint(2, 3));
chart1.Series[1].Points.Add(new DataPoint(3, 3));

chart1.Series[2].Points.Add(new DataPoint(0, 3));
chart1.Series[2].Points.Add(new DataPoint(1, 3));
//chart1.Series[2].Points.Add(new DataPoint(2, 0));
chart1.Series[2].Points.Add(new DataPoint(3, 3));

chart1.Series[3].Points.Add(new DataPoint(0, 3));
chart1.Series[3].Points.Add(new DataPoint(1, 3));
chart1.Series[3].Points.Add(new DataPoint(2, 3));
//chart1.Series[3].Points.Add(new DataPoint(3, 0));

chart1.SaveImage("C:\\Before.png", ChartImageFormat.Png);

Image of "before.png":

现在删除给定 x 值处没有数据点的系列的注释：

（注意！我发现，如果您在给定的 x 值处添加点，最后使 y = 0 的值 - 也就是在我保存图像之前，它不起作用。系列中点的顺序似乎很重要对于 StackedColumn，除了研究如何回答这个问题之外，我从未使用过这种类型，因此这可能是此类用户的常识）

chart1.Series.Clear();
chart1.Series.Add(new Series());
chart1.Series.Add(new Series());
chart1.Series.Add(new Series());
chart1.Series.Add(new Series());

foreach (Series s in chart1.Series)
{
    s.ChartType = SeriesChartType.StackedColumn;
}

chart1.Series[0].Points.Add(new DataPoint(0, 0));
chart1.Series[0].Points.Add(new DataPoint(1, 3));
chart1.Series[0].Points.Add(new DataPoint(2, 3));
chart1.Series[0].Points.Add(new DataPoint(3, 3));

chart1.Series[1].Points.Add(new DataPoint(0, 3));
chart1.Series[1].Points.Add(new DataPoint(1, 0));
chart1.Series[1].Points.Add(new DataPoint(2, 3));
chart1.Series[1].Points.Add(new DataPoint(3, 3));

chart1.Series[2].Points.Add(new DataPoint(0, 3));
chart1.Series[2].Points.Add(new DataPoint(1, 3));
chart1.Series[2].Points.Add(new DataPoint(2, 0));
chart1.Series[2].Points.Add(new DataPoint(3, 3));

chart1.Series[3].Points.Add(new DataPoint(0, 3));
chart1.Series[3].Points.Add(new DataPoint(1, 3));
chart1.Series[3].Points.Add(new DataPoint(2, 3));
chart1.Series[3].Points.Add(new DataPoint(3, 0));

// If you add the empty points here, it does not seem to work.  
// Empty points are as follows, and are already added above in the 'after' example.
// chart1.Series[0].Points.Add(new DataPoint(0, 0));
// chart1.Series[1].Points.Add(new DataPoint(1, 0));
// chart1.Series[2].Points.Add(new DataPoint(2, 0));
// chart1.Series[3].Points.Add(new DataPoint(3, 0));

chart1.SaveImage("C:\\After.png", ChartImageFormat.Png);

Image of "after.png":

因此，鉴于您无法在事后添加零点（尽管您可能能够插入它们？），您将需要将代码修改为如下所示：

var allPossibleGroups = t.StudentReports;

var groups = t.StudentReports
            .Where<StudentReport>(rep => rep.IsComplete && rep.FirstSaveTimestamp.HasValue)
            .GroupBy<StudentReport, DateTime>(rep => rep.FirstSaveTimestamp.Value.Date);

        bool hasPoints = false;
        foreach (var g in allPossibleGroups)
        {
            if(groups.ContainsKey(g))
            {
                series.Points.AddXY(g.Key, g.Count());
                hasPoints = true;
            }
            else
            {
                series.Points.AddXY(g.Key, 0);
            }
        }

抱歉，代码块很长，但是这个示例是必要的，它可以演示如何使其工作，而不会陷入在末尾添加空点（其中 y = 0）的陷阱，因为这是行不通的。

如果您需要更多帮助，请告诉我。