GridLine Annotations

GridLine annotations are lines or circles that cross the chart grid at a location on the axis, specified by their Value property.

Cartesian GridLine Annotation

In the case of RadCartesianChart, the CartesianGridLineAnnotation represents a vertical or horizontal line that crosses the entire plot area.

Example 1: Adding CartesianGridLineAnnotations

XAML

	<telerik:RadCartesianChart x:Name="cartesianChart">
		<telerik:RadCartesianChart.Annotations>
			<telerik:CartesianGridLineAnnotation Axis="{Binding ElementName=verticalAxis}" 
													Value="6"
													Stroke="Red"
													StrokeThickness="1"/>
			<telerik:CartesianGridLineAnnotation Axis="{Binding ElementName=horizontalAxis}" 
													Value="2.8"
													Stroke="Blue"
													StrokeThickness="1"/>
		</telerik:RadCartesianChart.Annotations>

		<telerik:RadCartesianChart.Series>
			<telerik:ScatterPointSeries>
				<telerik:ScatterPointSeries.DataPoints>
					<telerik:ScatterDataPoint XValue="1" YValue="5"/>
					<telerik:ScatterDataPoint XValue="3" YValue="2"/>
					<telerik:ScatterDataPoint XValue="4" YValue="7"/>
				</telerik:ScatterPointSeries.DataPoints>
			</telerik:ScatterPointSeries>
		</telerik:RadCartesianChart.Series>

		<telerik:RadCartesianChart.VerticalAxis>
			<telerik:LinearAxis x:Name="verticalAxis"/>
		</telerik:RadCartesianChart.VerticalAxis>

		<telerik:RadCartesianChart.HorizontalAxis>
			<telerik:LinearAxis x:Name="horizontalAxis"/>
		</telerik:RadCartesianChart.HorizontalAxis>
	</telerik:RadCartesianChart>

Figure 1: CartesianGridLineAnnotations in RadCartesianChart

Polar Axis GridLine Annotation

PolarAxisGridLineAnnotations represent concentric circles that cross the polar axis at the corresponding Value.

Example 2: Adding PolarAxisGridLineAnnotation

XAML

	<telerik:RadPolarChart>
		<telerik:RadPolarChart.Annotations>
			<telerik:PolarAxisGridLineAnnotation Value="2" Stroke="Red"/>
			<telerik:PolarAxisGridLineAnnotation Value="7" Stroke="LightGreen"/>
			<telerik:PolarAxisGridLineAnnotation Value="8" Stroke="LightBlue"/>
		</telerik:RadPolarChart.Annotations>

		<telerik:RadPolarChart.Series>
			<telerik:PolarPointSeries>
				<telerik:PolarPointSeries.DataPoints>
					<telerik:PolarDataPoint Value="2" Angle="30"/>
					<telerik:PolarDataPoint Value="7" Angle="90"/>
					<telerik:PolarDataPoint Value="8" Angle="230"/>
				</telerik:PolarPointSeries.DataPoints>
			</telerik:PolarPointSeries>
		</telerik:RadPolarChart.Series>

		<telerik:RadPolarChart.RadialAxis>
			<telerik:NumericRadialAxis/>
		</telerik:RadPolarChart.RadialAxis>

		<telerik:RadPolarChart.PolarAxis>
			<telerik:PolarAxis/>
		</telerik:RadPolarChart.PolarAxis>
	</telerik:RadPolarChart>

Figure 2: PolarAxisGridLineAnnotations in RadPolarChart

Radial Axis GridLine Annotation

RadialAxisGridLineAnnotations basically represent the radius of a RadPolarChart.

Example 3: Defining RadialAxisGridLineAnnotation

XAML

	<telerik:RadPolarChart>
		<telerik:RadPolarChart.Annotations>
			<telerik:RadialAxisGridLineAnnotation Value="30" Stroke="Red"/>
			<telerik:RadialAxisGridLineAnnotation Value="60" Stroke="LightGreen"/>
			<telerik:RadialAxisGridLineAnnotation Value="90" Stroke="LightBlue"/>
		</telerik:RadPolarChart.Annotations>

		<telerik:RadPolarChart.Series>
			<telerik:PolarPointSeries>
				<telerik:PolarPointSeries.DataPoints>
					<telerik:PolarDataPoint Value="2" Angle="30"/>
					<telerik:PolarDataPoint Value="7" Angle="90"/>
					<telerik:PolarDataPoint Value="8" Angle="230"/>
				</telerik:PolarPointSeries.DataPoints>
			</telerik:PolarPointSeries>
		</telerik:RadPolarChart.Series>

		<telerik:RadPolarChart.RadialAxis>
			<telerik:NumericRadialAxis/>
		</telerik:RadPolarChart.RadialAxis>

		<telerik:RadPolarChart.PolarAxis>
			<telerik:PolarAxis/>
		</telerik:RadPolarChart.PolarAxis>
	</telerik:RadPolarChart>

Figure 3: RadialAxisGridLineAnnotations in RadPolarChart

Properties

Common:

• DashArray : Gets or sets a collection of System.Double values that indicate the pattern of dashes and gaps that is used to outline annotations.

• Stroke : Gets or sets the System.Windows.Media.Brush that specifies how the annotations outline is painted.

• StrokeThickness : Gets or sets the width of the annotations stroke outline.

CartesianGridLineAnnotation:

• Axis : The CartesianGridLineAnnotation needs to be associated with horizontal or vertical axis explicitly.

• Value (of type object) : The place on the associated axis where the annotation crosses it. When the associated axis is numerical (Linear or Logarithmic) a numeric value is expected and when it is a CategoricalAxis - a category.

• Label : The string that is displayed in the label.

• LabelDefinition : Defines the position of the annotation label. Check the Annotation Labels help topic for more details.

PolarAxisGridLineAnnotations:

• Value (of type double) : Specifies the location on the polar axis (the radius), where the grid line will cross.

RadialAxisGridLineAnnotation:

• Value (of type object) : Specifies the location on the radial axis, where the grid line will cross. When the radial axis is NumericRadialAxis a numeric value is expected and when it is a CategoricalRadialAxis - a category.

See Also

• Custom Annotations
• MarkedZone Annotations
• AnnotationsProvider