EnvelopeIndicator Class

Namespace : DevExpress.XamarinForms.Charts

Assembly : DevExpress.XamarinForms.Charts.dll

NuGet Package : DevExpress.XamarinForms.Charts

Declaration

csharp

public class EnvelopeIndicator :
    CalculatedSeries

Remarks

An envelope indicator is a pair of lines that are offset at the specified percentage above and below a simple moving average.

Add an Indicator to a Series

This example demonstrates how to build a simple moving average envelope for Close values of a stock series.

Add the EnvelopeIndicator object to the chart’s collection of series (ChartView.Series).
Set the indicator’s Data property to a CalculatedSeriesDataAdapter class instance. Use this object’s Series property to specify a series for which the moving average envelope should be built.
Use the ValueLevel and PointsCount properties to specify the price level of a financial series point and the number of data points used to calculate the moving average.
Set the Factor property to a double value from 0 to 1 to specify the distance (as a percentage) between the moving average and an envelope line.

Note

When you specify the envelope indicator, the moving average line is not visible. To build and show it on the chart, add the MovingAverageIndicator object to the chart’s collection of series.

Xaml

xml

<dxc:ChartView x:Name="chart">
    <dxc:ChartView.Series>
        <dxc:StockSeries>
            <dxc:StockSeries.Data>
                <dxc:SeriesDataAdapter DataSource="{Binding StockPrices}" ArgumentDataMember="Date">
                    <dxc:ValueDataMember Type="High" Member="High" />
                    <dxc:ValueDataMember Type="Low" Member="Low" />
                    <dxc:ValueDataMember Type="Open" Member="Open" />
                    <dxc:ValueDataMember Type="Close" Member="Close" />
                </dxc:SeriesDataAdapter>
            </dxc:StockSeries.Data>
        </dxc:StockSeries>

        <dxc:EnvelopeIndicator ValueLevel="Close"
                               PointsCount="20"
                               Factor="0.04"
                               DisplayName="Moving Average Envelope">
            <dxc:EnvelopeIndicator.Data>
                <dxc:CalculatedSeriesDataAdapter Series="{Binding Series[0], Source={x:Reference chart}}"/>
            </dxc:EnvelopeIndicator.Data>
        </dxc:EnvelopeIndicator>
    </dxc:ChartView.Series>
</dxc:ChartView>

Customize Indicator Appearance

To change the envelope indicator appearance, set the Style property to the EnvelopeIndicatorStyle object and use this object’s properties to customize envelope lines and the area between them.

Xaml

xml

<dxc:EnvelopeIndicator>
    <dxc:EnvelopeIndicator.Style>
        <dxc:EnvelopeIndicatorStyle LowerStroke="#ff8fb1" LowerStrokeThickness="2" 
                                    UpperStroke="#ff8fb1" UpperStrokeThickness="2"
                                    Fill="#ff8fb1" Alpha="0.3"/>
    </dxc:EnvelopeIndicator.Style>

    <!--Indicator Data-->
</dxc:EnvelopeIndicator>

Implements

INotifyPropertyChanged

Inheritance

Object ChartSeriesElement SeriesBase Series CalculatedSeries EnvelopeIndicator