ValueDataMember Class

Specifies a data source field that contains data for series point values.

Namespace: DevExpress.XamarinForms.Charts

Assembly: DevExpress.XamarinForms.Charts.dll

NuGet Package: DevExpress.XamarinForms.Charts

Declaration

public class ValueDataMember :
    BindableObject

Remarks

ChartView supports two ways to populate series with data from an external data source.

Create series and bind them to data sources

Do the following to add series of different types to the chart and specify an individual data source for each series:

1. Add series to the ChartView.Series collection.

2. Set the Data property of a series to a SeriesDataAdapter object and specify this adapter’s properties:

   • DataSource
   • ArgumentDataMember
   • ValueDataMembers

See the following help topic for an example: Bind Chart Series to Data.

Generate series from a data source based on a template

You can set up the ChartView so that it uses the specified template to generate series from the bound data source. To do this, set the ChartView.SeriesDataTemplate property to a SeriesTemplateAdapter object and specify this adapter’s properties:

• DataSource
• SeriesDataMember
• SeriesTemplate
• ArgumentDataMember
• ValueDataMembers

See the following help topic for an example: Generate Series from a Data Source.

In both cases, ValueDataMembers is a collection of data source fields that contain data values for series points. The number of items in this collection (ValueDataMember objects) depends on the series type. Most series types (except for financial, range bar, range area, and bubble) require one value to build each point of the series.

Use the ValueDataMember.Type and ValueDataMember.Member properties to specify the value type and data source field that contains data for series point values.

Example

These examples show how to create and configure the data adapter to populate ChartView series of different types with data.

• For most series types supported by ChartView (besides financial, range bar and bubble charts), specify one ValueDataMember object with the Type set to Value:

  XAML

  <dxc:ChartView>
    <dxc:ChartView.Series>
      <dxc:LineSeries>
        <dxc:LineSeries.Data>
          <dxc:SeriesDataAdapter DataSource="{Binding GdpValues}" ArgumentDataMember="Year">
            <dxc:SeriesDataAdapter.ValueDataMembers>
              <dxc:ValueDataMember Type="Value" Member="Value"/>
            </dxc:SeriesDataAdapter.ValueDataMembers>
          </dxc:SeriesDataAdapter>
        </dxc:LineSeries.Data>
      </dxc:LineSeries>
    </dxc:ChartView.Series>
  </dxc:ChartView>
  

  Note

  ValueDataMembers is a content property. You can skip property tags in the markup.

• For financial series (CandleStickSeries and StockSeries), specify four ValueDataMember objects with Type set to High, Low, Open, and Close:

  XAML

  <dxc:ChartView>
    <dxc:ChartView.Series>
      <dxc:CandleStickSeries>
        <dxc:CandleStickSeries.Data>
          <dxc:SeriesDataAdapter DataSource="{Binding StockPrices}" ArgumentDataMember="Date">
              <dxc:ValueDataMember Type="High" Member="HighValue" />
              <dxc:ValueDataMember Type="Low" Member="LowValue" />
              <dxc:ValueDataMember Type="Open" Member="OpenValue" />
              <dxc:ValueDataMember Type="Close" Member="CloseValue" />
          </dxc:SeriesDataAdapter>
        </dxc:CandleStickSeries.Data>
      </dxc:CandleStickSeries>
    </dxc:ChartView.Series>
  </dxc:ChartView>
  

• For RangeBarSeries, specify two ValueDataMember objects with Type set to High and Low:

  XAML

  <dxc:ChartView>
      <dxc:ChartView.Series>
          <dxc:RangeBarSeries>
              <dxc:RangeBarSeries.Data>
                  <dxc:SeriesDataAdapter DataSource="{Binding OilPrices}" ArgumentDataMember="Month">
                      <dxc:ValueDataMember Type="High" Member="HighValue" />
                      <dxc:ValueDataMember Type="Low" Member="LowValue" />
                  </dxc:SeriesDataAdapter>
              </dxc:RangeBarSeries.Data>
          </dxc:RangeBarSeries>
      </dxc:ChartView.Series>
  </dxc:ChartView>
  

• For BubbleSeries, specify two ValueDataMember objects with Type set to Value and Weight:

  XAML

  <dxc:ChartView>
    <dxc:ChartView.Series>
      <dxc:BubbleSeries>
        <dxc:BubbleSeries.Data>
          <dxc:SeriesDataAdapter DataSource="{Binding HighestGrossingFilms}" ArgumentDataMember="Date">
              <dxc:ValueDataMember Type="Value" Member="Value" />
              <dxc:ValueDataMember Type="Weight" Member="WorldwideGrosses" />
          </dxc:SeriesDataAdapter>
        </dxc:BubbleSeries.Data>
      </dxc:BubbleSeries>
    </dxc:ChartView.Series>
  </dxc:ChartView>
  

Inheritance

Object

ValueDataMember