DataMember.ScaleType Property

Specifies the scale type of data in a column.

Namespace: DevExpress.UI.Xaml.Charts

Assembly: DevExpress.UI.Xaml.Charts.v19.2.dll

Declaration

C#

public ScaleType ScaleType { get; set; }

VB.NET

Public Property ScaleType As ScaleType

Property Value

Type	Description
ScaleType	A ScaleType object.

Available values:

Name	Description
Auto	A scale type is detected automatically based on the type of underlying data. This means that numerical data will be treated as numerical, date-time data as date-time, qualitative as qualitative values.
Numerical	Identifies the Numerical data scale. This means that data provided for the DataPointCollection.Points will be treated as numerical values, and will be shown on the axis as numbers (e.g., 100, 200, and 300).
DateTime	Identifies the DateTime data scale. This means that data provided for the DataPointCollection.Points will be treated as DateTime values, and will be shown on the axis as DateTime values (e.g., January, 2003, January, 2004, and January, 2005).
Qualitative	Identifies the Qualitative data scale. This means that data provided for the DataPointCollection.Points will be treated as qualitative values, and will be shown on the axis as textual representations (e.g., A, B, and C).

Remarks

For more information, refer to Providing Data.

Example

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

To do this, it is necessary to assign the DataSourceAdapter object to the Series.Data property and specify the datasource for the adapter via its DataSourceAdapter.DataSource property.

Note

A complete sample project is available at: https://github.com/DevExpress-Examples/how-to-bind-a-chart-to-data-e4362

XAML

<Page
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:Charts="using:DevExpress.UI.Xaml.Charts"
    xmlns:local="using:BindChart"
    x:Class="BindChart.MainPage"
    mc:Ignorable="d">

    <Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">

        <Charts:CartesianChart>
            <Charts:Series>
                <Charts:Series.View>
                    <Charts:LineSeriesView/>
                </Charts:Series.View>
                <Charts:Series.Data>
                    <Charts:DataSourceAdapter DataSource="{Binding ItemsSource}">
                        <Charts:DataMember DataMemberType="Argument" ColumnName="PointArgument" 
                                           ScaleType="DateTime"/>
                        <Charts:DataMember DataMemberType="Value" ColumnName="PointValue" 
                                           ScaleType="Auto"/>
                    </Charts:DataSourceAdapter>
                </Charts:Series.Data>
            </Charts:Series>
            <Charts:CartesianChart.AxisX>
                <Charts:AxisX DateTimeGridAlignment="Year" DateTimeMeasureUnit="Hour">
                    <Charts:AxisX.LabelOptions>
                        <Charts:AxisLabelOptions Pattern="{}{V:yyyy}"/>
                    </Charts:AxisX.LabelOptions>
                </Charts:AxisX>
            </Charts:CartesianChart.AxisX>
        </Charts:CartesianChart>
    </Grid>
</Page>

C#

using System;
using System.Collections;
using System.Collections.Generic;

namespace BindChart {

    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 ?? (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 = 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;
        }
    }
}

C#

using System;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace BindChart {

    public sealed partial class MainPage : Page {

        public MainPage() {
            this.InitializeComponent();
            DataContext = new ViewModel() {
                Start = 10000,
                Count = 50000,
                Step = TimeSpan.FromHours(3),
            };
        }

        protected override void OnNavigatedTo(NavigationEventArgs e) {
        }
    }
}