c# - Microsoft 图表控件 - 失败后重绘图表(红叉)

Question

我有一个 treeView element，其中每个节点代表一个双列表。

我正在使用 DataVisualization.Charting 控件来显示 list 中的值。

对于某些列表，在 RecalculateAxesScale (System.OverflowException:Value was either too large or too small for a Decimal)之后出现异常。 我忽略了这个错误，因此图表显示了一个大红叉。

当我现在点击另一个节点时，我想显示这个双列表的图表(这是有效的)，但我的图表没有被重新绘制。它始终显示红色 X。

我的代码:

private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
{

//Refresh chart:
chart1.Series.Clear();
chart1.ResetAutoValues();
chart1.ResetText();

//plot new doublelist
var series = new Series
{
   Name = "name",
   Color = color,
   ChartType = SeriesChartType.Line,
   ChartArea = "chartName"
};

this.chart1.Series.Add(series);
    series.Points.DataBindY(doubleList);
    var chartArea = chart1.ChartAreas["chartName"];
    chartArea.RecalculateAxesScale();
    chartArea.AxisX.Minimum = 1;
    chartArea.AxisX.Maximum = doubleList.Count;
    chartArea.CursorX.AutoScroll = true;
    chartArea.CursorY.AutoScroll = true;

    // Allow user to select area for zooming
    chartArea.CursorX.IsUserEnabled = true;
    chartArea.CursorX.IsUserSelectionEnabled = true;

    // Set automatic zooming`<br>
    chartArea.AxisX.ScaleView.Zoomable = true;
    chartArea.AxisY.ScaleView.Zoomable = true;
    chartArea.AxisX.ScrollBar.IsPositionedInside = true;

    //reset zoom
    chartArea.AxisX.ScaleView.ZoomReset();
    chart1.Invalidate();
}

[编辑]

dblList 的类型:

List<double> doubleList= (from s in myData select s.value).ToList(); 

完整的异常堆栈:

{System.OverflowException: Value was either too large or too small for a Decimal.
at System.Decimal.FCallMultiply(Decimal& d1, Decimal& d2)
at System.Decimal.op_Multiply(Decimal d1, Decimal d2)
at System.Windows.Forms.DataVisualization.Charting.Axis.RoundedValues(Double inter, Boolean shouldStartFromZero, Boolean autoMax, Boolean autoMin, Double& min, Double& max)
at System.Windows.Forms.DataVisualization.Charting.Axis.EstimateNumberAxis(Double& minimumValue, Double& maximumValue, Boolean shouldStartFromZero, Int32 preferredNumberOfIntervals, Boolean autoMaximum, Boolean autoMinimum)
at System.Windows.Forms.DataVisualization.Charting.Axis.EstimateAxis(Double& minimumValue, Double& maximumValue, Boolean autoMaximum, Boolean autoMinimum)
at System.Windows.Forms.DataVisualization.Charting.Axis.EstimateAxis()
at System.Windows.Forms.DataVisualization.Charting.ChartArea.SetDefaultAxesValues()
at System.Windows.Forms.DataVisualization.Charting.ChartArea.SetData(Boolean initializeAxes, Boolean checkIndexedAligned)

at System.Windows.Forms.DataVisualization.Charting.ChartArea.RecalculateAxesScale()

[编辑 2]

示例列表:

   List<double> dblList = new List<double>();
   dblList.Add(0.0);
   dblList.Add(-7.4876421623346545E-36);
   dblList.Add(1.0);
   dblList.Add(-26697097281536.0);
   dblList.Add(-6.8163553952838136E+28); //problem!!!!!

最后一个值产生问题(红叉无一异常(exception))。因此，转换列表的最小值和最大值似乎不合适。有什么想法吗？

 double min = (double)Decimal.MinValue; //min = -7.9228162514264338E+28
 double max = (double)Decimal.MaxValue; //max =  7.9228162514264338E+28

Answer 1

RecalculateAxesScale 中的错误(System.OverflowException:Value 对于 Decimal 而言太大或太小)被抛出，因为库中存在 Bug。它在图表函数的实现中使用了十进制值(尤其是在轴重新计算/缩放中)，这导致了问题。

只检查每个图表点的值是低于还是高于

double min = (double)Decimal.MinValue;
double max = (double)Decimal.MaxValue;

并用这个值替换它并没有解决问题。

我选择 -/+7.92E+27 作为边界而不是上面的边界，现在一切正常。