微软图表堆积柱形图有差距

Question

我正在使用 .Net 4.0 中的图表库来创建包含多个系列的堆积柱形图。我的目标是一个直方图，显示多个系列（教师）每天的累积行动（报告完成）数量。经常缺少数据（特定教师当天没有活动）。

当系列中缺少数据时，我会在条形中出现空白：

我的代码：

    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);
    }

如何删除

Answer 1

我有办法完成这项工作。
抱歉，答案很长，但我发现您尝试实施此答案的方式会影响它是否有效。

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

查看示例旁边的示例和生成的屏幕截图： 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));

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

“之前.png”的图像：

现在删除在给定 x 值处没有数据点的系列的 cmets：

（注意！我发现如果你在给定的 x 值处添加点到最后使 y = 0 的值 - 也就是在我保存图像之前，我发现它不起作用。系列中点的顺序似乎对 StackedColumn 很重要，我从来没有使用过这种类型，除了研究如何回答这个问题，以便这可能是这种类型用户的常识）

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);

“after.png”的图像：

因此，鉴于您不能在事后添加零点（尽管您可以插入它们？）您需要将您的代码修改为以下内容：

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，代码块太长了，但该示例是演示如何使其工作所必需的，而不会陷入在末尾添加空点（其中 y = 0）的陷阱，因为那将不起作用。

如果您需要更多帮助，请告诉我。

Answer 2

自己也遇到了同样的问题，想分享一下正确的解决方案：

使用 DataManipulator 插入缺失的 (x,y) 值：

foreach (Series s in chart.Series)
{
    chart.DataManipulator.Sort(PointSortOrder.Ascending, "X", s);
    chart.DataManipulator.InsertEmptyPoints(1, IntervalType.Number, s);
}

Answer 3

由于某种原因，循环通过系列对我不起作用，但下一个解决方案就像一个魅力：

Chart1.DataManipulator.InsertEmptyPoints(1, IntervalType.Number, "Series1, Series2, Series3, Series4")