IXYSeriesData Interface

The interface should be implemented by an object that provides data for Series.

Namespace: DevExpress.XamarinForms.Charts

Assembly: DevExpress.XamarinForms.Charts.dll

NuGet Package: DevExpress.XamarinForms.Charts

Declaration

public interface IXYSeriesData

Related API Members

The following members return IXYSeriesData objects:

• AreaSeries.Data
• BarSeriesBase.Data
• BubbleSeries.Data
• FinancialSeries.Data
• LineSeries.Data
• PointSeries.Data
• RangeAreaSeries.Data

Remarks

Objects that implement this interface provide user data values for Area Series, Line Series, Bar Series, Point Series, Bubble Series, Financial Series.

Note that various series can display data with a specific data type only (the GetDataType() method’s return value):

Series Type	GetDataType Return Value
Area Series	Qualitative, Numeric, DateTime
Line Series	Qualitative, Numeric, DateTime
Bar Series	Qualitative, Numeric, DateTime
Point Series	Qualitative, Numeric, DateTime
Bubble Series	WeightedQualitative, WeightedNumeric, WeightedDateTime
Financial Series	Financial

The interface provides GetValue and a set of GetArgument methods that return values by which the chart plots a series. Note that, parameters of GetValue method and concrete GetArgument method that the series call depend on data type the interface return:

Data Type	Called Methods and Their Arguments
Qualitative	GetQualitativeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value.
Numeric	GetNumericArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value.
DateTime	GetDateTimeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value.
WeightedQualitative	GetQualitativeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value and Weight.
WeightedNumeric	GetNumericArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value and Weight.
WeightedDateTime	GetDateTimeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value and Weight.
Financial	GetDateTimeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Open, High, Low and Close.

The series data type should correspond to the chart’s X-axis type. The following table lists axis-data matches:

Axis	Series Data Type
QualitativeAxisX	Qualitative, WeightedQualitative
NumericAxisX	Numeric, WeightedNumeric
DateTimeAxisX	DateTime, WeightedDateTime, Financial

Note

The chart creates an X-axis that matches the first series’ data if the chart does not have the specified X-axis.

Example

This example demonstrates how to populate a series with data:

XAML

<dxc:ChartView.Series>
    <dxc:LineSeries DisplayName="Stock">
        <dxc:LineSeries.Data>
            <data:StockSeriesData ItemsSource="{Binding Prices}"/>
        </dxc:LineSeries.Data>
    </dxc:LineSeries>
</dxc:ChartView.Series>

C#

using DXC = DevExpress.XamarinForms.Charts;

public class StockSeriesData : BindableObject, IXYSeriesData {
    public const string ItemsSourcePropertyName = "ItemsSource";

    public static readonly BindableProperty ItemsSourceProperty = BindableProperty.Create(
        propertyName: ItemsSourcePropertyName,
        returnType: typeof(IReadOnlyList<StockPrice>),
        declaringType: typeof(StockSeriesData),
        defaultValue: null);

    public IReadOnlyList<StockPrice> ItemsSource {
        get => (IReadOnlyList<StockPrice>)GetValue(ItemsSourceProperty);
        set => SetValue(ItemsSourceProperty, value);
    }

    public SeriesDataType GetDataType() => SeriesDataType.DateTime;
    public int GetDataCount() => ItemsSource.Count;
    public DateTime GetDateTimeArgument(int index) => ItemsSource[index].Date;
    public double GetValue(DXC.ValueType valueType, int index) {
        switch (valueType) {
            case DXC.ValueType.Value: return ItemsSource[index].Close;
            default: return 0;
        }
    }
    public object GetKey(int index) => ItemsSource[index];

    public double GetNumericArgument(int index) => 0;
    public string GetQualitativeArgument(int index) => string.Empty; 
}

The code above uses the following classes and members:

Symbol	Description
LineSeries	Displays data as points connected by a line.
LineSeries.Data	Gets or sets the series data.
IXYSeriesData	The interface should be implemented by an object that provides data for Series.