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NumericConstantLineCollection Class

The collection of NumericConstantLine objects.

Namespace: DevExpress.XamarinForms.Charts

Assembly: DevExpress.XamarinForms.Charts.dll

NuGet Package: DevExpress.XamarinForms.Charts

Declaration

public class NumericConstantLineCollection :
    ChartCollection<NumericConstantLine>

The following members return NumericConstantLineCollection objects:

Remarks

A numeric constant line is a vertical or horizontal straight line that passes through the chart and indicates an x- or y-axis’s value.

Numeric Constant Line Sample

Each axis can have any number of constant lines. A numeric axis (NumericAxisY or NumericAxisX ) holds its constant lines in the NumericConstantLineCollection collection which the NumericAxisY.ConstantLines or NumericAxisX.ConstantLines property returns.

Example

This example shows how to add a constant line to a numeric y-axis, customize its appearance and show it in the chart legend. To do this, add a NumericConstantLine object with the specified properties to the NumericAxisY.ConstantLines collection.

NumericAxisY Constant Line

<dxc:ChartView>
  <!--...-->

  <dxc:ChartView.AxisY>
      <dxc:NumericAxisY>
          <dxc:NumericAxisY.ConstantLines>
              <dxc:NumericConstantLine AxisValue="{Binding ViewModel.NightTempAverage}"
                                       ShowBehind="True"
                                       VisibleInLegend="True"
                                       LegendText="Average Annual">
                  <!-- Customize the constant line title. -->
                  <dxc:NumericConstantLine.Title>
                      <dxc:ConstantLineTitle Text="{Binding ViewModel.NightTempAverage, StringFormat='{0}°C'}"
                                             Alignment="Far" 
                                             ShowBelowLine="False">
                          <dxc:ConstantLineTitle.Style>
                              <dxc:TitleStyle>
                                  <dxc:TitleStyle.TextStyle>
                                      <dxc:TextStyle Color="#7f43bf" Size="12"/>
                                  </dxc:TitleStyle.TextStyle>
                              </dxc:TitleStyle>
                          </dxc:ConstantLineTitle.Style>
                      </dxc:ConstantLineTitle>
                  </dxc:NumericConstantLine.Title>
                  <!-- Customize the constant line appearance. -->
                  <dxc:NumericConstantLine.Style>
                      <dxc:ConstantLineStyle Stroke="#7f43bf" Thickness="2" Dashes="7 3"/>
                  </dxc:NumericConstantLine.Style>
              </dxc:NumericConstantLine>
          </dxc:NumericAxisY.ConstantLines>
      </dxc:NumericAxisY>
  </dxc:ChartView.AxisY>
</dxc:ChartView>
See Also