Polarlabels - Livecharts2

DataLabels

{{~ if name != "Pie series" ~~}} :::info The following block uses the PieChart class as an example but all labels in polar series work the same way. ::: {{~~ end ~}}

Data labels are labels for every point in a series, there are multiple properties to customize them, take a look at the following sample:

csharp

Series { get; set; } = new List<ISeries>
{
    new PieSeries<double>
    {
        Values = new List<double> { 8 },
        DataLabelsPaint = new SolidColorPaint(SKColors.Black),
        DataLabelsSize = 22,
        // for more information about available positions see:
        // {{ website_url }}/api/{{ version }}/LiveChartsCore.Measure.PolarLabelsPosition
        DataLabelsPosition = LiveChartsCore.Measure.PolarLabelsPosition.Middle,
        DataLabelsFormatter = point => point.Coordinate.PrimaryValue.ToString("N2") + " elements"
    },
    new PieSeries<double>
    {
        Values = new List<double> { 6 },
        DataLabelsPaint = new SolidColorPaint(SKColors.Black),
        DataLabelsSize = 22,
        DataLabelsPosition = LiveChartsCore.Measure.PolarLabelsPosition.Middle,
        DataLabelsFormatter = point => point.Coordinate.PrimaryValue.ToString("N2") + " elements"
    },
    new PieSeries<double>
    {
        Values = new List<double> { 4 },
        DataLabelsPaint = new SolidColorPaint(SKColors.Black),
        DataLabelsSize = 22,
        DataLabelsPosition = LiveChartsCore.Measure.PolarLabelsPosition.Middle,
        DataLabelsFormatter = point => point.Coordinate.PrimaryValue.ToString("N2") + " elements"
    }
};

The series above result in the following chart:

You can also use the DataLabelsRotation property to set an angle in degrees for the labels in the chart, notice the constants LiveCharts.CotangentAngle and LiveCharts.TangentAngle to build labels rotation.

This is the result when we set all the series to LiveCharts.CotangentAngle:

And this is the result when we set all the series to LiveCharts.TangentAngle:

Finally you can also combine tangent and cotangent angles with decimal degrees:

csharp

Series { get; set; } = new List<ISeries>
{
    new PieSeries<double>
    {
        DataLabelsRotation = 30, // in degrees
    },
    new PieSeries<double>
    {
        DataLabelsRotation = LiveCharts.TangentAngle + 30, // the tangent + 30 degrees
    },
    new PieSeries<double>
    {
        DataLabelsRotation = LiveCharts.CotangentAngle + 30, // the cotangent + 30 degrees
    }
};