corelibraries-devexpress-dot-xtracharts-dot-datamember.md
Gets or sets the type of data member values.
Namespace : DevExpress.XtraCharts
Assembly : DevExpress.XtraCharts.v25.2.dll
NuGet Package : DevExpress.Charts
public ScaleType ScaleType { get; set; }
Public Property ScaleType As ScaleType
| Type | Description |
|---|---|
| ScaleType |
The data member scale type.
|
Available values:
| Name | Description |
|---|---|
| Qualitative |
Identifies the Qualitative data scale. This means that data provided for the Series.Points will be treated as qualitative values and will be shown on the axis as textual representations (e.g., A , B , and C ).
| | Numerical |
Identifies the Numerical data scale. This means that data provided for the Series.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 Series.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 ). Note that in this case the AxisBase.DateTimeOptions property is used to define the output format of DateTime values shown on the axis.
| | TimeSpan |
Identifies the TimeSpan data scale. The data that you provide for the Series.Points will be treated and shown on the axis as TimeSpan values (for example, 00:00:00 , 00:00:01 , 00:00:02 ). Note that in this case, the axis’s TimeSpanScaleOptions property allows you to specify the scale-related settings. To define the output format of TimeSpan values shown on the axis, use the AxisBase.Label‘s TextPattern property.
| | Auto |
The scale type is automatically determined according to the real type of underlying data.
|
This example shows how to create a series that requires one value per argument and populate it with data.
Create a DataSourceAdapter object.
Define the adapter DataSourceAdapter.DataSource property.
Populate the adapter DataSourceAdapterBase.DataMembers collection. You should specify data members that contain arguments and values.
Use the Series.DataAdapter property to assign the adapter to the series.
using DevExpress.Utils;
using DevExpress.XtraCharts;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
namespace ChartDataAdapters {
public partial class Form1 : Form {
readonly TemperatureData temperatureData = new TemperatureData(new Random(9));
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
// Create a series.
Series series = new Series("Temperature", ViewType.Spline);
// Create a data adapter.
DataSourceAdapter dataAdapter = new DataSourceAdapter();
// Specify the data source.
dataAdapter.DataSource = temperatureData.Points;
// Create a data member that defines arguments.
dataAdapter.DataMembers.Add(new DataMember {
DataMemberType = ChartDataMemberType.Argument,
ColumnName = "TimeStamp",
ScaleType = ScaleType.TimeSpan
});
// Create a data member that defines values.
dataAdapter.DataMembers.Add(new DataMember {
DataMemberType = ChartDataMemberType.Value,
ColumnName = "Temperature",
ScaleType = ScaleType.Numerical
});
// Assign the data adapter to the series.
series.DataAdapter = dataAdapter;
}
}
class TemperatureData {
const int PointsCount = 250;
readonly TemperaturePoint maxTemperaturePoint = new TemperaturePoint(TimeSpan.Zero, double.MinValue);
readonly TemperaturePoint minTemperaturePoint = new TemperaturePoint(TimeSpan.MaxValue, double.MaxValue);
readonly List<TemperaturePoint> points = new List<TemperaturePoint>(PointsCount);
internal TemperaturePoint MaxTemperaturePoint {
get { return maxTemperaturePoint; }
}
internal TemperaturePoint MinTemperaturePoint {
get { return minTemperaturePoint; }
}
internal double OptimalTemperature {
get { return 53; }
}
internal List<TemperaturePoint> Points {
get { return points; }
}
internal TemperatureData(Random random) {
double preTemperature = 50;
for (int i = 0; i < PointsCount; i++) {
TimeSpan time = TimeSpan.FromSeconds(i);
double temperature = preTemperature + (random.NextDouble() - 0.5) * 10;
if (temperature > 90)
temperature -= 20;
if (temperature < 20)
temperature += 10;
TemperaturePoint temperaturePoint = new TemperaturePoint(time, temperature);
if (temperature < minTemperaturePoint.Temperature)
minTemperaturePoint = temperaturePoint;
if (temperature > maxTemperaturePoint.Temperature)
maxTemperaturePoint = temperaturePoint;
points.Add(temperaturePoint);
preTemperature = temperature;
}
}
}
public class TemperaturePoint {
public TimeSpan TimeStamp { get; private set; }
public double Temperature { get; private set; }
internal TemperaturePoint(TimeSpan time, double temperature) {
this.TimeStamp = time;
this.Temperature = temperature;
}
}
}
Imports DevExpress.Utils
Imports DevExpress.XtraCharts
Imports System
Imports System.Collections.Generic
Imports System.Windows.Forms
Namespace ChartDataAdapters
Public Partial Class Form1
Inherits Form
Private ReadOnly temperatureData As TemperatureData = New TemperatureData(New Random(9))
Public Sub New()
InitializeComponent()
End Sub
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
' Create a series.
Dim series As Series = New Series("Temperature", ViewType.Spline)
' Create a data adapter.
Dim dataAdapter As DataSourceAdapter = New DataSourceAdapter()
' Specify the data source.
dataAdapter.DataSource = temperatureData.Points
' Create a data member that defines arguments.
dataAdapter.DataMembers.Add(New DataMember With {
.DataMemberType = ChartDataMemberType.Argument,
.ColumnName = "TimeStamp",
.ScaleType = ScaleType.TimeSpan
})
' Create a data member that defines values.
dataAdapter.DataMembers.Add(New DataMember With {
.DataMemberType = ChartDataMemberType.Value,
.ColumnName = "Temperature",
.ScaleType = ScaleType.Numerical
})
' Assign the data adapter to the series.
series.DataAdapter = dataAdapter
End Sub
End Class
Friend Class TemperatureData
Const PointsCount As Integer = 250
Private ReadOnly maxTemperaturePointField As TemperaturePoint = New TemperaturePoint(TimeSpan.Zero, Double.MinValue)
Private ReadOnly minTemperaturePointField As TemperaturePoint = New TemperaturePoint(TimeSpan.MaxValue, Double.MaxValue)
Private ReadOnly pointsField As List(Of TemperaturePoint) = New List(Of TemperaturePoint)(PointsCount)
Friend ReadOnly Property MaxTemperaturePoint As TemperaturePoint
Get
Return maxTemperaturePointField
End Get
End Property
Friend ReadOnly Property MinTemperaturePoint As TemperaturePoint
Get
Return minTemperaturePointField
End Get
End Property
Friend ReadOnly Property OptimalTemperature As Double
Get
Return 53
End Get
End Property
Friend ReadOnly Property Points As List(Of TemperaturePoint)
Get
Return pointsField
End Get
End Property
Friend Sub New(ByVal random As Random)
Dim preTemperature As Double = 50
For i As Integer = 0 To PointsCount - 1
Dim time As TimeSpan = TimeSpan.FromSeconds(i)
Dim temperature As Double = preTemperature + (random.NextDouble() - 0.5) * 10
If temperature > 90 Then temperature -= 20
If temperature < 20 Then temperature += 10
Dim temperaturePoint As TemperaturePoint = New TemperaturePoint(time, temperature)
If temperature < minTemperaturePointField.Temperature Then minTemperaturePointField = temperaturePoint
If temperature > maxTemperaturePointField.Temperature Then maxTemperaturePointField = temperaturePoint
pointsField.Add(temperaturePoint)
preTemperature = temperature
Next
End Sub
End Class
Public Class TemperaturePoint
Private _TimeStamp As System.TimeSpan, _Temperature As Double
Public Property TimeStamp As TimeSpan
Get
Return _TimeStamp
End Get
Private Set(ByVal value As TimeSpan)
_TimeStamp = value
End Set
End Property
Public Property Temperature As Double
Get
Return _Temperature
End Get
Private Set(ByVal value As Double)
_Temperature = value
End Set
End Property
Friend Sub New(ByVal time As TimeSpan, ByVal temperature As Double)
TimeStamp = time
Me.Temperature = temperature
End Sub
End Class
End Namespace
See Also