Data Label in WinUI Chart (SfPolarChart)

24 Jun 202214 minutes to read

Data labels are used to display values related to a chart segment. Values from data points(x, y) or other custom properties from a data source can be displayed.

Each data label can be represented by the following:

  • Label - displays the segment label content at the (X, Y) point.
  • Connector line - used to connect the (X, Y) point and the label element.

Enable Data Label

The ShowDataLabels property of a series is used to enable the data labels.

<chart:SfPolarChart>
    ...
    <chart:PolarAreaSeries ShowDataLabels="True"
                    ItemsSource="{Binding Data}"  
                    XBindingPath="Product" 
                    YBindingPath="SalesRate"/>
    ...
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
PolarAreaSeries series = new PolarAreaSeries();
series.ShowDataLabels = true;
...

Data label in WinUI chart

Context

To customize the content of data labels, need to define DataLabelSettings of series and set Context property of DataLabelSettings to define the value to be displayed as label content.

<chart:SfPolarChart>
    <chart:PolarAreaSeries ShowDataLabels="True"
                        ItemsSource="{Binding PlantDetails}" 
                        XBindingPath="Direction"
                        YBindingPath="Tree">
    <chart:PolarAreaSeries.DataLabelSettings>
        <chart:PolarDataLabelSettings Context="Percentage"/>
    </chart:PolarAreaSeries.DataLabelSettings>

    </chart:PolarAreaSeries>
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
...
PolarAreaSeries series = new PolarAreaSeries();
series.ShowDataLabels = true;
series.DataLabelSettings = new PolarDataLabelSettings() {Context = LabelContext.Percentage };
...

Data label support in WinUI chart

Customization

The following properties are used to customize the data label.

  • BorderBrush- used to change the border color.
  • BorderThickness- used to change the thickness of the border.
  • Margin- used to change the margin size for label.
  • FontStyle- used to change font style of the label.
  • FontSize- used to change font size of the label.
  • Foreground- used to change the text color of the label.
  • FontFamily- used to change the font family of the label.
  • Background- used to change the label background color.
<chart:SfPolarChart>
    ...
    <chart:PolarAreaSeries ItemsSource="{Binding PlantDetails}" 
                            XBindingPath="Direction" 
                            YBindingPath="Tree"
                            ShowDataLabels="True">
                <chart:PolarAreaSeries.DataLabelSettings>
                    <chart:PolarDataLabelSettings Foreground="White" FontSize="12" FontFamily="Calibri" BorderBrush="White"                             BorderThickness="1" Margin="1" FontStyle="Italic" Background="#1E88E5">
                    </chart:PolarDataLabelSettings>
                </chart:PolarAreaSeries.DataLabelSettings>
    </chart:PolarAreaSeries>
    ...
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
...
PolarAreaSeries series = new PolarAreaSeries();
series.ShowDataLabels = true;
series.DataLabelSettings = new PolarDataLabelSettings() 
{ 
    Foreground = new SolidColorBrush(Colors.White),
    BorderBrush = new SolidColorBrush(Colors.White),
    Background = new SolidColorBrush(Color.FromArgb(255, 30, 136, 229)),
    BorderThickness = new Thickness(1),
    Margin = new Thickness(1),
    FontStyle = FontStyle.Italic,
    FontFamily = new FontFamily("Calibri"),
    FontSize = 12
};
...

Data label customization support in WinUI Chart

Template

The appearance of the data label can be customized using the ContentTemplate property of PolarDataLabelSettings as shown in the following code example.

<Grid x:Name="grid">
    <Grid.Resources>
        <DataTemplate x:Key="datalabelTemplate">
                <Grid>
                    <Ellipse
                            Width="30"
                            Height="30"
                            HorizontalAlignment="Left"
                            VerticalAlignment="Top"
                            Fill="White"
                            Stroke="#0078DE"
                             StrokeThickness="2" />
                    <TextBlock
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center"
                            FontFamily="Segoe UI"
                            FontSize="12"
                            Foreground="#FF585858"
                            Text="{Binding}"
                            TextWrapping="Wrap" />
                </Grid>
        </DataTemplate>
    </Grid.Resources>
    <chart:SfPolarChart x:Name="chart">
    ...
        <chart:PolarAreaSeries ShowDataLabels="True">
            <chart:PolarAreaSeries.DataLabelSettings>
                <chart:PolarDataLabelSettings ContentTemplate="{StaticResource datalabelTemplate}" />
            </chart:PolarAreaSeries.DataLabelSettings>
        </chart:PolarAreaSeries>
    ...
    </chart:SfPolarChart>
</Grid>
SfPolarChart chart = new SfPolarChart();
...
PolarAreaSeries series = new PolarAreaSeries();
series.ShowDataLabels = true;

series.DataLabelSettings = new PolarDataLabelSettings() 
{ 
    ContentTemplate = grid.Resources["datalabelTemplate"] as DataTemplate,
};
...

Template support for data label in WinUI Chart

Format

The Format property can be used to format the data labels.

<chart:SfPolarChart x:Name="chart">
    ...
    <chart:PolarLineSeries ShowDataLabels="True">
        <chart:PolarLineSeries.DataLabelSettings>
            <chart:PolarDataLabelSettings Format="#.0"/>
        </chart:PolarLineSeries.DataLabelSettings>
    </chart:PolarLineSeries>
    ...
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
. . . 
PolarLineSeries series = new PolarLineSeries();
series.ShowDataLabels = true;

series.DataLabelSettings = new PolarDataLabelSettings() 
{ 
    Format = "#.0",
};
...

Label format support for data label in WinUI Chart

Rotation

Rotation property is used to define the angle to which the label has to rotate.

<chart:SfPolarChart x:Name="chart">
...
    <chart:PolarLineSeries ShowDataLabels="True"  
                            ItemsSource="{Binding PlantDetails}" 
                            XBindingPath="Direction" 
                            YBindingPath="Tree">
        <chart:PolarLineSeries.DataLabelSettings>
            <chart:PolarDataLabelSettings Rotation="-45"/>
        </chart:PolarLineSeries.DataLabelSettings>
    </chart:PolarLineSeries>
    ...
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
. . . 
PolarLineSeries series = new PolarLineSeries();
series.ShowDataLabels = true;

series.DataLabelSettings = new PolarDataLabelSettings() 
{ 
    Rotation = -45,
};
...

Rotation support for data label in WinUI Chart

Applying Series Fill

The UseSeriesPalette property is used to set the Fill of the series to the data label background.

<chart:SfPolarChart x:Name="chart">
...
    <chart:PolarLineSeries ShowDataLabels="True"  
                            ItemsSource="{Binding PlantDetails}" 
                            XBindingPath="Direction" 
                            YBindingPath="Tree">
        <chart:PolarLineSeries.DataLabelSettings>
            <chart:PolarDataLabelSettings UseSeriesPalette="True"/>
        </chart:PolarLineSeries.DataLabelSettings>
    </chart:PolarLineSeries>
    ...
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
. . . 
PolarLineSeries series = new PolarLineSeries();
series.ShowDataLabels = true;
series.DataLabelSettings = new PolarDataLabelSettings()
{
    UseSeriesPalette = true,
};
...

Applying UseSeriesPalette in WinUI Chart

Connector Line

Connector line is used to connect label and data point using a line. ShowConnectorLine property of PolarDataLabelSettings is used to enable the connector line in the polar chart.

The connector line can be customized using the following properties:

<chart:SfPolarChart x:Name="chart">
...
    <chart:PolarLineSeries ShowDataLabels="True"  
                            ItemsSource="{Binding PlantDetails}" 
                            XBindingPath="Direction" 
                            YBindingPath="Tree">
        <chart:PolarLineSeries.DataLabelSettings>
            <chart:PolarDataLabelSettings ShowConnectorLine="True" ConnectorHeight="25" 
                                          ConnectorRotation="45"/>
        </chart:PolarLineSeries.DataLabelSettings>
    </chart:PolarLineSeries>
    ...
</chart:SfPolarChart>
SfPolarChart chart = new SfPolarChart();
. . . 
PolarLineSeries series = new PolarLineSeries();
series.ShowDataLabels = true;
series.DataLabelSettings = new PolarDataLabelSettings()
{
    ShowConnectorLine = true,
    ConnectorHeight = 25,
    ConnectorRotation = 45,
};
...

ConnectorLine in WinUI Chart