ConstantLineBase Class

The base class for constant lines.

Namespace : DevExpress.XamarinForms.Charts

Assembly : DevExpress.XamarinForms.Charts.dll

NuGet Package : DevExpress.XamarinForms.Charts

Declaration

csharp

public class ConstantLineBase :
    StyledElement

Remarks

A constant line is used to visually represent an axis value as a line perpendicular to the axis to which it belongs.

The ConstantLineBase class contains settings that are common to all types of constant lines (DateTimeConstantLine, NumericConstantLine and QualitativeConstantLine ). For example, you can use this class’ properties to specify a constant line title, appearance, visibility.

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.

XAML

xaml

<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>

Implements

INotifyPropertyChanged

Inheritance

Object ChartElement StyledElement ConstantLineBase DateTimeConstantLine

NumericConstantLine

QualitativeConstantLine