CategoricalAxis LabelFormat and LabelTemplateSelector

[Jonathan]

Hello,

I have a problem with the horizontal axis of my RadCartesianChar when I change the period of my statistics:

<telerik:RadCartesianChart x:Name="Chart"
                           TrackBallInfoStyle="{StaticResource ResourceKey=TrackBallInfoStyle}"
                           TrackBallLineStyle="{StaticResource ResourceKey=TransparentTrackLineStyle}"
                           helpers:ChartViewUtilities.ChartAlignmentGroup="g1">

    <telerik:RadCartesianChart.Resources>
        <DataTemplate x:Key="NormalTemplate">
            <TextBlock Text="{Binding}"
                       Padding="2"/>
        </DataTemplate>
        <DataTemplate x:Key="TodayTemplate">
            <Border BorderThickness="1" BorderBrush="Black">
                <TextBlock Text="{Binding}"
                           Padding="2"/>
            </Border>
        </DataTemplate>
        <DataTemplate x:Key="HolidayTemplate">
            <TextBlock Text="{Binding}"
                       FontWeight="Bold"
                       Foreground="Red"
                       Padding="2"/>
        </DataTemplate>
        <DataTemplate x:Key="WeekendTemplate">
            <TextBlock Text="{Binding}"
                       FontWeight="Bold"
                       Foreground="Black"
                       Padding="2"/>
        </DataTemplate>

        <selectors:DateTypeTemplateSelector x:Key="Selector"
                                            NormalTemplate="{StaticResource NormalTemplate}"
                                            TodayTemplate="{StaticResource TodayTemplate}"
                                            HolidayTemplate="{StaticResource HolidayTemplate}"
                                            WeekendTemplate="{StaticResource WeekendTemplate}"/>
    </telerik:RadCartesianChart.Resources>

    <telerik:RadCartesianChart.Behaviors>
        <telerik:ChartTrackBallBehavior ShowTrackInfo="True"
                                        helpers:ChartViewUtilities.ShouldPositionTrackBallCloseToDataPoint="True"
                                        helpers:ChartViewUtilities.TrackedPointFill="{StaticResource IsMouseOverNeutralValueBrush}"
                                        helpers:ChartViewUtilities.TrackBallGroup="g1"
                                        TrackInfoUpdated="ChartTrackBallBehavior_TrackInfoUpdated"/>
    </telerik:RadCartesianChart.Behaviors>

    <telerik:RadCartesianChart.Grid>
        <telerik:CartesianChartGrid MajorLinesVisibility="Y" />
    </telerik:RadCartesianChart.Grid>

    <telerik:RadCartesianChart.HorizontalAxis>
        <telerik:DateTimeCategoricalAxis LabelFormat="dd"
                                         LabelTemplateSelector="{StaticResource Selector}"/>
    </telerik:RadCartesianChart.HorizontalAxis>

    <telerik:RadCartesianChart.VerticalAxis>
        <telerik:LinearAxis SmartLabelsMode="SmartStepAndRange" MajorStep="1" />
    </telerik:RadCartesianChart.VerticalAxis>

    <telerik:BarSeries ItemsSource="{Binding SeaDailyStats}"
                       CategoryBinding="DateAction"
                       ValueBinding="NbAction"
                       CombineMode="Stack"
                       helpers:ChartAnimationUtilities.CartesianAnimation="Rise">

        <telerik:BarSeries.TrackBallInfoTemplate>
            <DataTemplate>
                <Border>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding DisplayContent, StringFormat='Mise(s) en ligne : {0}'}" />
                    </StackPanel>
                </Border>
            </DataTemplate>
        </telerik:BarSeries.TrackBallInfoTemplate>

        <telerik:BarSeries.DefaultVisualStyle>
            <Style TargetType="{x:Type Border}">
                <Setter Property="Background" Value="{StaticResource NeutralValueBrush}"/>
            </Style>
        </telerik:BarSeries.DefaultVisualStyle>
    </telerik:BarSeries>

    <telerik:BarSeries ItemsSource="{Binding SeaDailyStats}"
                       CategoryBinding="DateAction"
                       ValueBinding="Target"
                       CombineMode="Stack"
                       helpers:ChartAnimationUtilities.CartesianAnimation="Rise">

        <telerik:BarSeries.TrackBallInfoTemplate>
            <DataTemplate />
        </telerik:BarSeries.TrackBallInfoTemplate>

        <telerik:BarSeries.DefaultVisualStyle>
            <Style TargetType="Border">
                <Setter Property="Background" Value="{StaticResource BadValueBrush}"/>
            </Style>
        </telerik:BarSeries.DefaultVisualStyle>

    </telerik:BarSeries>
</telerik:RadCartesianChart>

 

The period is a complete month but I display only the day (dd) on horizontal axis.

The template selector allow me to display differently the type of day (normal, today, week end, holiday).

The first month all is correct but when I change the month, the SelectTemplate method of DateTypeTemplateSelector is not call again. So the template don't change with the new axis value of the month.

But if I display not only the day (dd) but the complete day (dd/MM/yyyy) on LabelFormat all works fine.

So I think that the SelectTemplate method of DateTypeTemplateSelector is call only when the displayed value is different.

But me I need o display only the day (dd).

Can you help me please. Thank you in advance and sorry for my bad English.

Kind regards,

Jonathan

[Jonathan]

Sorry it's for WPF and not for Silverlight

[Dinko | Tech Support Engineer]

Hello Jonathan,

Thank you for contacting us.

They are calculated and drawn based on the minimum, maximum and the step of the axis (or on the number of distinct categories if the axis is categorical). This means that the LabelTemplateSelector of the axis won't listen for changes in the underlying data, but instead will listen for changes in the labels plotted on the axis.

For example, if the axis is Categorical and you insert a data point in the existing category the chart won't add new label for the axis and the label template selector won't fire, but if you add new category, there will be new label and the selector will fire to determine what template to use. That is why in your case the template selector is not fired.

To workaround this behavior you can reset every time the LabelTemplateSelector of the DateTimeCategoricalAxis when you change the collection of the chart.

(this.Chart.HorizontalAxis as DateTimeCategoricalAxis).LabelTemplateSelector = null;
(this.Chart.HorizontalAxis as DateTimeCategoricalAxis).LabelTemplateSelector = this.Chart.Resources["Selector"] as DateTypeTemplateSelector;

Hope this information is helpful.

Regards,
Dinko
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