RadChart clears data series on zoom

[Nikos]

Version: 2013 Q1 with SP1

In a RadChart with zoom enabled, trying to zoom-in causes automatic removal of the underlying DataSeries object from the ChartArea.DataSeries collection. I have attached some sample code that reproduces the issue. Note that this behavior is reproduced both programatically, and through UI interaction (by resizing the zoom bar).

XAML code:

<Window
    x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525"
    xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
    Loaded="Window_Loaded">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <telerik:RadChart
        Name="chart" telerik:StyleManager.Theme="Summer" MaxWidth="5000" MaxHeight="5000"
        FontFamily="Segoe UI" FontSize="10" Background="Transparent" PaletteBrushesRepeat="False">
            <telerik:RadChart.DefaultView>
                <telerik:ChartDefaultView>
                    <telerik:ChartDefaultView.ChartLegend>
                        <telerik:ChartLegend
                        Name="chLegend" Background="Transparent" UseAutoGeneratedItems="True"
                        FontSize="9" IsHitTestVisible="False"/>
                    </telerik:ChartDefaultView.ChartLegend>
                    <telerik:ChartDefaultView.ChartArea>
                        <telerik:ChartArea EnableAnimations="True" LegendName="chLegend">
                            <telerik:ChartArea.AxisX>
                                <telerik:AxisX/>
                            </telerik:ChartArea.AxisX>
                            <telerik:ChartArea.AxisY>
                                <telerik:AxisY/>
                            </telerik:ChartArea.AxisY>
                            <telerik:ChartArea.AnimationSettings>
                                <telerik:AnimationSettings TotalSeriesAnimationDuration="00:00:00.600" />
                            </telerik:ChartArea.AnimationSettings>
                            <telerik:ChartArea.DataSeries>
                                <telerik:DataSeries LegendLabel="Product Sales">
                                    <telerik:DataSeries.Definition>
                                        <telerik:BarSeriesDefinition/>
                                    </telerik:DataSeries.Definition>
                                </telerik:DataSeries>
                            </telerik:ChartArea.DataSeries>
                        </telerik:ChartArea>
                    </telerik:ChartDefaultView.ChartArea>
                </telerik:ChartDefaultView>
            </telerik:RadChart.DefaultView>
        </telerik:RadChart>

        <Button x:Name="btnSetZoom" Grid.Row="1" Padding="3" Content="Click to set zoom" HorizontalAlignment="Right" Click="btnSetZoom_Click"/>
    </Grid>
</Window>

VB code behind:

Imports Telerik.Windows.Controls.Charting

Class MainWindow

    Private Sub btnSetZoom_Click(sender As System.Object, e As System.Windows.RoutedEventArgs)
        Me.SetZoom()
    End Sub

    Private Sub Window_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs)
        Me.InitChart()
        Me.GenerateData()
    End Sub

    Private Sub InitChart()
        With Me.chart.DefaultView.ChartArea.AxisX
            .AutoRange = True
            .IsZeroBased = True
        End With
        With Me.chart.DefaultView.ChartArea.AxisX
            .AutoRange = True
            .IsZeroBased = True
        End With

        Dim zoomX As ZoomScrollSettings = chart.DefaultView.ChartArea.ZoomScrollSettingsX
        zoomX.ScrollMode = ScrollMode.ScrollAndZoom
        zoomX.RangeStart = 0
        zoomX.RangeEnd = 1
        Dim zoomY As ZoomScrollSettings = chart.DefaultView.ChartArea.ZoomScrollSettingsY
        zoomY.ScrollMode = ScrollMode.ScrollAndZoom
        zoomY.RangeStart = 0
        zoomY.RangeEnd = 1
    End Sub

    Private Sub GenerateData()
        Dim data As New List(Of DataPoint)()

        For Each i In Enumerable.Range(0, 20)
            Dim p = New DataPoint(i, i + 1.0)
            data.Add(p)
        Next

        Me.chart.DefaultView.ChartArea.DataSeries(0).AddRange(data)
    End Sub

    Private Sub SetZoom()
        Dim zoomX As ZoomScrollSettings = chart.DefaultView.ChartArea.ZoomScrollSettingsX
        zoomX.RangeStart = 0.2
        zoomX.RangeEnd = 0.7
    End Sub

End Class

[Peshito]

Hi,

Zooming and Scrolling feature is available in data bound scenarios only! Additional requirement is an ItemMapping with DataPointMember set to XValue or XCategory. You can find more information here.

Hope this helps.

Greetings,
Peshito
the Telerik team

[Nikos]

The constraint you mention does not apply in our current version, i.e. RadControls WPF Q3 2010. We just noticed this behavior while evaluating the 2013 Q1 SP1.

So we might assume that after some point, RadChart does not support zoom on unbound data, as it did?

[Peshito]

Hello,

Zooming and scrolling feature is intended to work in data bound scenarios only. At some time there might have been an issue with it, which I assume has let you use it in a different scenario like the one you have for example. I also tried your scenario with the Q3 2010 RadControls version and I found that the zooming works on your vertical axis only.

In order to have properly working Zooming and Scrolling feature, please use it in a data bound scenario.

Regards,
Peshito
the Telerik team