Hit Testing

In This Topic

In NOV Chart for .NET hit testing is achieved by subscribing to one of the keyboard or mouse events exposed by the NChartElement class. This class is similar to the Input element class in NOV UI and for more information you can visit the Input Elements topic. The following code snippet shows how to implement an interactive pie chart:

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NChartView chartView = new NChartView(); // create a dock panel with label and chart NDockPanel dockPanel = new NDockPanel(); chartView.Surface.Content = dockPanel; // crete a docked label NLabel label = new NLabel(); label.Text = "Interactive Pie Chart"; label.Margins = new NMargins(10); NDockLayout.SetDockArea(label, ENDockArea.Top); dockPanel.AddChild(label); // create a new cartesian chart NPieChart pieChart = new NPieChart(); NDockLayout.SetDockArea(pieChart, ENDockArea.Center); dockPanel.AddChild(pieChart); NPieSeries pieSeries = new NPieSeries(); pieChart.Series.Add(pieSeries); pieSeries.DataPoints.Add(CreateDataPoint(10)); pieSeries.DataPoints.Add(CreateDataPoint(20)); pieSeries.DataPoints.Add(CreateDataPoint(30)); ... private NPieDataPoint CreateDataPoint(double value) { NPieDataPoint pieDataPoint = new NPieDataPoint(value); pieDataPoint.MouseDown += new Function<NMouseButtonEventArgs>(pieDataPoint_MouseDown); return pieDataPoint; } void pieDataPoint_MouseDown(NMouseButtonEventArgs arg) { NPieDataPoint pieDataPoint = (NPieDataPoint)arg.TargetNode; pieDataPoint.Fill = new NColorFill(NColor.Red); }

Copy Code

NChartView chartView = new NChartView();

// create a dock panel with label and chart
NDockPanel dockPanel = new NDockPanel();
chartView.Surface.Content = dockPanel;

// crete a docked label
NLabel label = new NLabel();
label.Text = "Interactive Pie Chart";
label.Margins = new NMargins(10);
NDockLayout.SetDockArea(label, ENDockArea.Top);
dockPanel.AddChild(label);

// create a new cartesian chart
NPieChart pieChart = new NPieChart();
NDockLayout.SetDockArea(pieChart, ENDockArea.Center);
dockPanel.AddChild(pieChart);

NPieSeries pieSeries = new NPieSeries();
pieChart.Series.Add(pieSeries);
pieSeries.DataPoints.Add(CreateDataPoint(10));
pieSeries.DataPoints.Add(CreateDataPoint(20));
pieSeries.DataPoints.Add(CreateDataPoint(30));

...

private NPieDataPoint CreateDataPoint(double value)

{

NPieDataPoint pieDataPoint = new NPieDataPoint(value);
pieDataPoint.MouseDown += new Function<NMouseButtonEventArgs>(pieDataPoint_MouseDown);
return pieDataPoint;

}

void pieDataPoint_MouseDown(NMouseButtonEventArgs arg)

{

NPieDataPoint pieDataPoint = (NPieDataPoint)arg.TargetNode;
pieDataPoint.Fill = new NColorFill(NColor.Red);

}

In this example when the user clicks on a pie slice it will turn red.

UI

Input Elements