Selection

1 Mar 20223 minutes to read

SFChart supports selection that enables you to select a segment in a series or series itself.

Data Point Selection

You can select a data point by tapping on it. To enable the selection feature, set EnableDataPointSelection property as True for series.

C#

SFColumnSeries series           = new SFColumnSeries ();

series.EnableDataPointSelection = true;

Following properties are used to configure the selection feature,

• SelectedDataPointIndex – used to programmatically select a data point
• SelectedDataPointColor – used to change the selected data point color

C#

SFColumnSeries series           = new SFColumnSeries ();

series.EnableDataPointSelection = true;

series.SelectedDataPointIndex   = 2;

series.SelectedDataPointColor   = UIColor.Red;

NOTE

For Accumulation series like pie, doughnut, pyramid and funnel, when you select a data point, the corresponding legend item also will be selected.

Series Selection

Series selection is used in case of multiple series when you want to highlight a particular series. Series Selection can be enabled by setting EnableSeriesSelection property to true. The SeriesSelectionColor property is used to set the color to highlight the series.

C#

chart.EnableSeriesSelection = true;
...

SFColumnSeries series = new SFColumnSeries();
series.Color = UIColor.FromRGB(174, 235, 231);
...

SFColumnSeries series1 = new SFColumnSeries();
series1.Color = UIColor.FromRGB(211, 190, 229);
...

SFColumnSeries series2 = new SFColumnSeries();
series2.Color = UIColor.FromRGB(192, 216, 240);

To set the series selection color,

C#

chart.SeriesSelectionColor = UIColor.FromRGB(0, 155, 247);

Delegates

We need to implement delegate to deal with the user interactions in chart for data point selection. In order to do this,you need to adopt the SFChartDelegate protocol through the class extension as shown below.

C#

public override void ViewDidLoad ()
{
    chart.Delegate = new ChartDelegate ();
}

public class ChartDelegate : SFChartDelegate
{
    public override void DidDataPointSelect (SFChart chart, SFChartSelectionInfo info)
    {

    }
}

WillDataPointSelect

The WillDataPointSelect delegate is called when the series datapoint selection operation has been started, the argument includes the SFChartSelectionChangingInfo which is used to get the selection state. The argument contains the following information.

• SelectedSeries – used to get the series of selected data point.
• SelectedSegment - used to get the segment of selected data point.
• SelectedDataPointIndex – used to get the selected data point index.
• PreviousSelectedIndex – used to get the previous selected data point index.
• PreviousSelectedSeries - used to get the previous selected series.
• Cancel – used to set the value indicating whether the selection should be canceled.

DidDataPointSelect

The DidDataPointSelect delegate is called when the series datapoint selection operation has been started, the argument includes the SFChartSelectionInfo which is used to get the selection state. The argument contains the following information.

• SelectedSeries – used to get the series of selected data point.
• SelectedSegment - used to get the segment of selected data point.
• SelectedDataPointIndex – used to get the selected data point index.
• PreviousSelectedIndex – used to get the previous selected data point index.
• PreviousSelectedSeries - used to get the previous selected series.