C# WinForms MSChart（StackedBar - 甘特图）带 Y 轴日期限制

Question

UPDATE: From what I've seen, this has little to do with the date itself. It's simply a case of having a long bar on the chart, when focusing in on a short segment of it (Date/Time, Short value ranges, etc), then it stops coloring the bar. Still no idea why or how to fix it, other than turning a blind eye to it.

I've been attempting to solve a weird little error involving stacked charts and date restrictions. Say you set the Y Axis as Dates, the X Axis is projects, and you use the bars as project completion, project deadline and project overdue.

Now if you set the minimum and maximum dates shown on the Y Axis to a few days apart, on a project expected to last months, you will see the problem. The bar loses its color, though if you increase the gap between minimum and maximum then the problem goes away.

Below is a snippit of the code involved:

    private void _Gantt_Load(object sender, EventArgs e)
    {
        chart1.MouseUp                      += new MouseEventHandler(MouseHandler);

        _dtpGraphStart.ValueChanged         += new EventHandler(DateTimeHandler);
        _dtpGraphEnd.ValueChanged           += new EventHandler(DateTimeHandler);

        string pOneName = "Project 1";
        string pTwoName = "Project 2";
        DateTime pOneStart = new DateTime(2011, 01, 01, 0, 0, 0);
        DateTime pTwoStart = new DateTime(2011, 02, 01, 12, 0, 0);
        DateTime pOneEnd = new DateTime(2011, 01, 01, 15, 0, 0);
        DateTime pTwoEnd = new DateTime(2011, 07, 01, 7, 0, 0);
        double pOneTotal = (pOneEnd - pOneStart).TotalDays;
        double pTwoTotal = (pTwoEnd - pTwoStart).TotalDays;
        double pOnePercent = 75;
        double pTwoPercent = 50;
        double pOneComplete = (pOnePercent / 100.0f) * pOneTotal;
        double pTwoComplete = (pTwoPercent / 100.0f) * pTwoTotal;

        chart1.Series["StartSeries"].Points.AddXY(pOneName, pOneStart);
        chart1.Series["StartSeries"].Points.AddXY(pTwoName, pTwoStart);
        chart1.Series["ProjectDurationSeries"].Points.AddXY(pOneName, pOneComplete);
        chart1.Series["ProjectDurationSeries"].Points.AddXY(pTwoName, pTwoComplete);
        chart1.Series["ProjectDurationSeries"].Points[0].Tag = "TestOne";
        chart1.Series["ProjectDurationSeries"].Points[1].Tag = "TestTwo";
        chart1.Series["ProjectRemainingSeries"].Points.AddXY(pOneName, pOneTotal - pOneComplete);
        chart1.Series["ProjectRemainingSeries"].Points.AddXY(pTwoName, pTwoTotal - pTwoComplete);
        chart1.Series["ProjectRemainingSeries"].Points[0].Tag = "TestCompleteOne";
        chart1.Series["ProjectRemainingSeries"].Points[1].Tag = "TestCompleteTwo";
        chart1.ChartAreas[0].AxisY.Minimum = new DateTime(DateTime.Today.Year, DateTime.Today.Month, DateTime.Today.Day,  0,  0,  0).ToOADate();
        chart1.ChartAreas[0].AxisY.Maximum = new DateTime(DateTime.Today.Year, DateTime.Today.Month, DateTime.Today.Day, 23, 59, 59).ToOADate();
        chart1.DataBind();

        _dtpGraphEnd.MinDate = _dtpGraphStart.Value;
        _dtpGraphStart.MaxDate = _dtpGraphEnd.Value;
    }

    private void DateTimeHandler(object sender, EventArgs e)
    {
        DateTimePicker dtp = (DateTimePicker)sender;

        switch (dtp.Name)
        {
            case "_dtpGraphStart":
                chart1.ChartAreas[0].AxisY.Minimum = new DateTime(dtp.Value.Year, dtp.Value.Month, dtp.Value.Day, 0, 0, 0).ToOADate();
                _dtpGraphEnd.MinDate = dtp.Value;
                break;
            case "_dtpGraphEnd":
                chart1.ChartAreas[0].AxisY.Maximum = new DateTime(dtp.Value.Year, dtp.Value.Month, dtp.Value.Day, 23, 59, 59).ToOADate();
                _dtpGraphStart.MaxDate = dtp.Value;
                break;
        }

        if ((chart1.ChartAreas[0].AxisY.Maximum - chart1.ChartAreas[0].AxisY.Minimum) < 3)
            chart1.ChartAreas[0].AxisY.LabelStyle.Format = "T";
        if (((chart1.ChartAreas[0].AxisY.Maximum - chart1.ChartAreas[0].AxisY.Minimum) > 3) 
            && ((chart1.ChartAreas[0].AxisY.Maximum - chart1.ChartAreas[0].AxisY.Minimum) < 30))
            chart1.ChartAreas[0].AxisY.LabelStyle.Format = "dd/MM";
        if ((chart1.ChartAreas[0].AxisY.Maximum - chart1.ChartAreas[0].AxisY.Minimum) > 30)
            chart1.ChartAreas[0].AxisY.LabelStyle.Format = "MM/yyyy";
    }

The above has Projects spanning from 01/01/2011 00:00:00 to 01/01/2011 15:00:00, and 01/02/2011 12:00:00 to 01/07/2011 07:00:00.

Initially the date restriction is on todays date, for no particular reason.

Heres an image displaying the issue. No other code has anything to do with what this graph displays, other than minor property changes, but for the sake of being thorough, I'll add those below from the designer file.

        chartArea1.AxisX.MajorGrid.Enabled = false;
        chartArea1.AxisY.InterlacedColor = System.Drawing.Color.Lime;
        chartArea1.AxisY.LabelStyle.Format = "T";
        chartArea1.AxisY.MajorGrid.Enabled = false;
        chartArea1.Name = "ChartArea1";
        this.chart1.ChartAreas.Add(chartArea1);
        this.chart1.Location = new System.Drawing.Point(0, 0);
        this.chart1.Name = "chart1";
        series1.ChartArea = "ChartArea1";
        series1.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
        series1.Color = System.Drawing.Color.White;
        series1.Name = "StartSeries";
        series2.BorderColor = System.Drawing.Color.Black;
        series2.BorderWidth = 2;
        series2.ChartArea = "ChartArea1";
        series2.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
        series2.Color = System.Drawing.Color.FromArgb(((int)(((byte)(0)))), ((int)(((byte)(192)))), ((int)(((byte)(0)))));
        series2.EmptyPointStyle.Color = System.Drawing.Color.FromArgb(((int)(((byte)(0)))), ((int)(((byte)(192)))), ((int)(((byte)(0)))));
        series2.Name = "ProjectDurationSeries";
        series3.BackHatchStyle = System.Windows.Forms.DataVisualization.Charting.ChartHatchStyle.ForwardDiagonal;
        series3.BackSecondaryColor = System.Drawing.Color.White;
        series3.BorderColor = System.Drawing.Color.Black;
        series3.BorderWidth = 2;
        series3.ChartArea = "ChartArea1";
        series3.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
        series3.Color = System.Drawing.Color.FromArgb(((int)(((byte)(128)))), ((int)(((byte)(128)))), ((int)(((byte)(255)))));
        series3.Name = "ProjectRemainingSeries";
        series4.BackHatchStyle = System.Windows.Forms.DataVisualization.Charting.ChartHatchStyle.ForwardDiagonal;
        series4.BorderColor = System.Drawing.Color.Black;
        series4.BorderWidth = 2;
        series4.ChartArea = "ChartArea1";
        series4.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
        series4.Color = System.Drawing.Color.Red;
        series4.Name = "Series4";
        this.chart1.Series.Add(series1);
        this.chart1.Series.Add(series2);
        this.chart1.Series.Add(series3);
        this.chart1.Series.Add(series4);
        this.chart1.Size = new System.Drawing.Size(727, 339);
        this.chart1.TabIndex = 0;
        this.chart1.Text = "chart1";

Heres an image displaying the problem: http://i55.tinypic.com/27zkv0w.jpg

Answer 1

chartArea1.AxisX.MajorGrid.Enabled = false;
chartArea1.AxisY.InterlacedColor = System.Drawing.Color.Lime;
chartArea1.AxisY.LabelStyle.Format = "T";
chartArea1.AxisY.MajorGrid.Enabled = false;
chartArea1.Name = "ChartArea1";
this.chart1.ChartAreas.Add(chartArea1);
this.chart1.Location = new System.Drawing.Point(0, 0);
this.chart1.Name = "chart1";
series1.ChartArea = "ChartArea1";
series1.ChartType =
System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
series1.Color = System.Drawing.Color.White;
series1.Name = "StartSeries";
series2.BorderColor = System.Drawing.Color.Black;
series2.BorderWidth = 2;
series2.ChartArea = "ChartArea1";
series2.ChartType = 
System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
series2.Color = System.Drawing.Color.FromArgb(((int)(((byte)(0)))), ((int)(((byte) 
(192)))), ((int)(((byte)(0)))));
series2.EmptyPointStyle.Color = System.Drawing.Color.FromArgb(((int)(((byte)(0)))), 
((int)(((byte)(192)))), ((int)(((byte)(0)))));
series2.Name = "ProjectDurationSeries";
series3.BackHatchStyle = 
System.Windows.Forms.DataVisualization.Charting.ChartHatchStyle.ForwardDiagonal;
series3.BackSecondaryColor = System.Drawing.Color.White;
series3.BorderColor = System.Drawing.Color.Black;
series3.BorderWidth = 2;
series3.ChartArea = "ChartArea1";
series3.ChartType = 
System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
series3.Color = System.Drawing.Color.FromArgb(((int)(((byte)(128)))), ((int)
(((byte)(128)))), ((int)(((byte)(255)))));
series3.Name = "ProjectRemainingSeries";
series4.BackHatchStyle = 
System.Windows.Forms.DataVisualization.Charting.ChartHatchStyle.ForwardDiagonal;
series4.BorderColor = System.Drawing.Color.Black;
series4.BorderWidth = 2;
series4.ChartArea = "ChartArea1";
series4.ChartType = 
System.Windows.Forms.DataVisualization.Charting.SeriesChartType.StackedBar;
series4.Color = System.Drawing.Color.Red;
series4.Name = "Series4";
this.chart1.Series.Add(series1);
this.chart1.Series.Add(series2);
this.chart1.Series.Add(series3);
this.chart1.Series.Add(series4);
this.chart1.Size = new System.Drawing.Size(727, 339);
this.chart1.TabIndex = 0;
this.chart1.Text = "chart1";