DataSource.PointSource Property

Specifies a source of points.

Namespace: DevExpress.WinUI.Charts

Assembly: DevExpress.WinUI.Charts.v23.2.dll

NuGet Package: DevExpress.WinUI

Declaration

C#

[DP(null, Handler = "PointSourceChanged")]
public object PointSource { get; set; }

VB.NET

<DP(Nothing, Handler:="PointSourceChanged")>
Public Property PointSource As Object

Property Value

Type	Description
Object	An object that is a point source.

Remarks

You can use an object that implements the IEnumerable, IList, IListSource, or IBindingList interface to specify the PointSource property.

Use the following properties to define the names of data fields that store point arguments and values:

• DataSource.ArgumentDataMember
• DataSource.ValueDataMember

Example

The following example demonstrates how to bind a chart to data from a ViewModel.

To do this, it is necessary to assign the DataSource object to the Series.Data property and specify the data source for the adapter in its DataSource.PointSource property.

XAML

<Window
    x:Class="DataSourceExample.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:DataSourceExample"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:Charts="using:DevExpress.WinUI.Charts"
    mc:Ignorable="d">

    <Grid>
        <Charts:CartesianChart x:Name="chart">
            <Charts:Series>
                <Charts:Series.View>
                    <Charts:LineSeriesView/>
                </Charts:Series.View>
                <Charts:Series.Data>
                    <Charts:DataSource PointSource="{Binding ItemsSource}" 
                                       ArgumentDataMember="PointArgument" 
                                       ValueDataMember="PointValue"/>
                </Charts:Series.Data>
            </Charts:Series>
            <Charts:CartesianChart.AxisX>
                <Charts:AxisX DateTimeGridAlignment="Year" 
                              DateTimeMeasureUnit="Hour" 
                              LabelPattern="{}{V:yyyy}"/>
            </Charts:CartesianChart.AxisX>
        </Charts:CartesianChart>
    </Grid>
</Window>

C#

using Microsoft.UI.Xaml;
using System;
using System.Collections;
using System.Collections.Generic;

namespace DataSourceExample {

    public sealed partial class MainWindow : Window {
        public MainWindow() {
            this.InitializeComponent();
            chart.DataContext = new ViewModel() {
                Start = 10000,
                Count = 50000,
                Step = TimeSpan.FromHours(3),
            };
        }
    }
    public class DateTimeDataPoint {
        public DateTime PointArgument { get; set; }
        public double PointValue { get; set; }
    }

    public class ViewModel {
        DateTime start = new DateTime(2000, 1, 1);
        IEnumerable itemsSource;
        readonly Random random = new Random();


        public TimeSpan Step { get; set; }
        public int Count { get; set; }
        public double Start { get; set; }
        public IEnumerable ItemsSource {
            get { return itemsSource ??= CreateItemsSource(Count); }
        }

        protected IEnumerable CreateItemsSource(int count) {
            var points = new List<DateTimeDataPoint>();

            double value = GenerateStartValue(random);
            points.Add(new DateTimeDataPoint() { PointArgument = start, PointValue = value });
            for (int i = 1; i < count; i++) {
                value += GenerateAddition(random);
                start += Step;
                points.Add(new DateTimeDataPoint() { PointArgument = start, PointValue = value });
            }
            return points;
        }

        protected double GenerateStartValue(Random random) {
            return Start + random.NextDouble() * 100;
        }

        protected double GenerateAddition(Random random) {
            double factor = random.NextDouble();
            if (factor == 1)
                factor = 50;
            else if (factor == 0)
                factor = -50;
            return (factor - 0.5) * 50;
        }
    }
}