IXYSeriesData Interface

An interface that should be implemented by an object that supplies data for the chart’s 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:

• XYSeries.Data

Remarks

Assign objects that implement this interface to the Data property of Area, Line, Bar, Point, Bubble, RangeBar, RangeArea and Financial series to supply user data values for series that the ChartView displays.

Each series type can display data of specific data types 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
Range Series	RangeQualitative, RangeNumeric, RangeDateTime
Financial Series	Financial

The IXYSeriesData interface has the GetValue method and a set of GetArgument methods that return values used to plot a series on the chart. A value type parameter of the GetValue method and the GetArgument method that the series calls depend on the data type the interface returns:

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.
RangeQualitative	GetQualitativeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value1 and Value2.
RangeNumeric	GetNumericArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value1 and Value2.
RangeDateTime	GetDateTimeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Value1 and Value2.
Financial	GetDateTimeArgument(Int32); GetValue(ValueType, Int32) with the value type set to Open, High, Low and Close.

The series data type should be compatible with the chart’s X-axis type as the following table shows:

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

Note

The chart automatically chooses the X-axis type depending on data in the first series if you do not specify an axis explicitly.

Example

This example demonstrates how to populate a line 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	An interface that should be implemented by an object that supplies data for the chart’s series.