ConstantLine.Legend Property

Specifies a legend (or its View Model) that contains the constant line's legend item.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v20.1.dll

Declaration

public object Legend { get; set; }
Public Property Legend As Object

Property Value

Type Description
Object

An object of a legend's View Model class or the Legend object.

Examples

The Chart Control can generate its child elements from their ViewModels. This is useful when the application uses the MVVM architecture and the Chart should contain several chart elements that are bound to data. You can bind the element's ItemsSource to the View Model's property to generate a chart element collection from a chart's View Model. Then specify the element's ItemTemplate or ItemTemplateSelector to bind the element's properties to the element view model's properties. For example, you can bind a chart's legend collection to the view model's legend collection using the ChartControlBase.LegendItemsSource and configure the generated legends using the ChartControlBase.LegendItemTemplate.

Imports System
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
Imports System.Globalization
Imports System.IO
Imports System.Xml.Linq

Namespace MvvmSample.Model
    Friend Class WeatherInfo
        Private privateTimestamp As Date
        Public Property Timestamp() As Date
            Get
                Return privateTimestamp
            End Get
            Private Set(ByVal value As Date)
                privateTimestamp = value
            End Set
        End Property
        Private privateTemperature As Double
        Public Property Temperature() As Double
            Get
                Return privateTemperature
            End Get
            Private Set(ByVal value As Double)
                privateTemperature = value
            End Set
        End Property
        Private privatePressure As Integer
        Public Property Pressure() As Integer
            Get
                Return privatePressure
            End Get
            Private Set(ByVal value As Integer)
                privatePressure = value
            End Set
        End Property
        Private privateRelativeHumidity As Integer
        Public Property RelativeHumidity() As Integer
            Get
                Return privateRelativeHumidity
            End Get
            Private Set(ByVal value As Integer)
                privateRelativeHumidity = value
            End Set
        End Property

        Public Sub New(ByVal timestamp As Date, ByVal temperature As Double, ByVal pressure As Integer, ByVal relativeHumidity As Integer)
            Me.Timestamp = timestamp
            Me.Temperature = temperature
            Me.Pressure = pressure
            Me.RelativeHumidity = relativeHumidity
        End Sub
    End Class

    Friend Interface WeatherProvider
        ReadOnly Property WeatherInfos() As IEnumerable(Of WeatherInfo)
    End Interface

    Friend Class XmlWeatherProvider
        Implements WeatherProvider

        Private filename As String
        Public Sub New(ByVal filename As String)
            If File.Exists(filename) Then
                Me.filename = filename
            Else
                Throw New Exception(String.Format("The '{0}' file does not exist.", filename))
            End If
        End Sub

        Private infos As Collection(Of WeatherInfo)
        Public ReadOnly Property WeatherInfos() As IEnumerable(Of WeatherInfo) Implements WeatherProvider.WeatherInfos
            Get
                If infos Is Nothing Then
                    Dim doc As XDocument = XDocument.Load(filename)

                    infos = New Collection(Of WeatherInfo)()
                    For Each element As XElement In doc.Element("WeatherData").Elements("WeatherInfo")
                        infos.Add(New WeatherInfo(timestamp:= Date.Parse(element.Element("Timestamp").Value, CultureInfo.InvariantCulture), temperature:= Double.Parse(element.Element("Temperature").Value, CultureInfo.InvariantCulture), pressure:= Integer.Parse(element.Element("Pressure").Value, CultureInfo.InvariantCulture), relativeHumidity:= Integer.Parse(element.Element("RelativeHumidity").Value, CultureInfo.InvariantCulture)))
                    Next element
                End If
                Return infos
            End Get
        End Property
    End Class
End Namespace
See Also