Invalid code in documentation.

[Nick]

Just so you know, there are multiple errors here: http://www.telerik.com/help/wpf/radchartview-axes-datetimeaxes.html (XAML and VB).

[Giuseppe]

Hello Nick,

Indeed you are correct -- we will forward your feedback to our techincal writers so they can review and update the help topic(s).

Here is the correct code for your reference:

XAML

<UserControl x:Class="SilverlightApplication16_vb.MainPage"
    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:telerik="http://schemas.telerik.com/2008/xaml/presentation"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">

        <telerik:RadCartesianChart x:Name="chart">
            <telerik:RadCartesianChart.HorizontalAxis>
                <telerik:DateTimeContinuousAxis LabelFitMode="MultiLine"
                                    LabelFormat="MMM yyyy"/>
            </telerik:RadCartesianChart.HorizontalAxis>

            <telerik:RadCartesianChart.VerticalAxis>
                <telerik:LinearAxis/>
            </telerik:RadCartesianChart.VerticalAxis>

            <telerik:RadCartesianChart.Series>
                <telerik:LineSeries Stroke="Orange" StrokeThickness="2"/>
            </telerik:RadCartesianChart.Series>

        </telerik:RadCartesianChart>

    </Grid>
</UserControl>

VB.NET

Imports Telerik.Windows.Controls.ChartView

Partial Public Class MainPage
    Inherits UserControl

    Public Sub New()
        InitializeComponent()

        Dim lastDate As DateTime = DateTime.Now
        Dim lastVal As Double = 20

        Dim dataSource As List(Of ChartDataObject) = New List(Of ChartDataObject)
        For i As Integer = 0 To 5 Step 1
            Dim obj As ChartDataObject = New ChartDataObject
            obj.[Date] = lastDate.AddMonths(1)
            obj.Value = lastVal
            dataSource.Add(obj)

            lastVal += 1
            lastDate = obj.[Date]
        Next

        Dim series As LineSeries = DirectCast(Me.chart.Series(0), LineSeries)

        Dim categoryBinding As PropertyNameDataPointBinding = New PropertyNameDataPointBinding
        categoryBinding.PropertyName = "Date"

        Dim valueBinding As PropertyNameDataPointBinding = New PropertyNameDataPointBinding
        valueBinding.PropertyName = "Value"

        series.CategoryBinding = categoryBinding
        series.ValueBinding = valueBinding
        series.ItemsSource = dataSource
    End Sub

End Class

Public Class ChartDataObject
    Dim _date As Date
    Dim _value As Double

    Public Property [Date]() As DateTime
        Get
            Return Me._date
        End Get
        Set(value As DateTime)
            Me._date = value
        End Set
    End Property

    Public Property Value() As Double
        Get
            Return Me._value
        End Get
        Set(value As Double)
            Me._value = value
        End Set
    End Property
End Class

We have updated your Telerik points as well.


Best wishes,
Giuseppe
the Telerik team

[Nick]

Thanks.  Unfortunately, the code still does not run.  I get:  "The property 'Stroke' does not exist in XML namespace 'http://schemas.telerik.com/2008/xaml/presentation" on the XAML side.  

If I remove those attributes (just to get passed that error), the VB throws the error: 'Add value to collection of type 'Telerik.Windows.Controls.ChartView.PresenterCollection(Telerik.Windows.Controls.ChartView.CartesianSeries)' threw an exception.' Line number '23' and line position '22'.

[Giuseppe]

Hello Nick,

We double-checked the code and it works as expected on our end -- we have attached runnable sample projects (WPF/SL) for your reference.

Hope this helps.


Regards,
Giuseppe
the Telerik team

[Nick]

Same errors for me after copying/pasting your code.  Could this be a result of having Q1, Q2 and Q3 installed at the same time?

[Nick]

OK.  Found the problem.  The code samples do not work if you have a reference to both Telerik.Windows.Controls.Charting and Telerik.Windows.Controls.Chart in the same project.  The problem stems from the fact that there is ambiguity between the Charting and Chart references that are not handled in the sample/example code.  This is a problem for me particularly because I am in the process of replacing the Charts in my project with the ChartView control to see if that alleviates the memory leak that occurs when using the Chart control.

[Nick]

OK, I have successfully swapped out theChart with the ChartView.  Without making any other changes, the application (which streams real-time data) is at least 5x faster!  

In my old setup, I had tooltips, pointmarks, etc. all turned off on the chart controls, which were bound to observable collections and I limited the sampling to 6000 (10 minutes of rolling data).   The application would always crash on my machine after about 1.5-2 hours streaming the data (outofmemoryexception).   I tried everything-- even automatically calling gc.collect every 10 seconds.  Nothing quelled the Chart controls' hunger for more and more memory.  

This control, although only in beta, is leaps and bounds faster at real-time data.  Kudos to you,Telerik.  You have officially resolved the last major hurdle we had to ship our SCADA software (which also uses your treeview, griview, menu, map and input controls).

A minor question I still had was, how do I change the color of the X and Y axis labels?  I can seem to find that in the documentation.

Thanks!

[Giuseppe]

Hi Nick,

You can achieve the desired effect by setting the Axis.LabelStyle property like this:

<Grid x:Name="LayoutRoot" Background="White">
    <Grid.Resources>
        <Style x:Key="LabelStyle" TargetType="TextBlock">
            <Setter Property="Foreground" Value="Red" />
        </Style>
    </Grid.Resources>

    <telerik:RadCartesianChart x:Name="RadChart1">
        <telerik:BarSeries>
            <telerik:BarSeries.DataPoints>
                <telerik:CategoricalDataPoint Value="2" />
                <telerik:CategoricalDataPoint Value="1" />
                <telerik:CategoricalDataPoint Value="4" />
                <telerik:CategoricalDataPoint Value="5" />
                <telerik:CategoricalDataPoint Value="6" />
            </telerik:BarSeries.DataPoints>
        </telerik:BarSeries>

        <telerik:RadCartesianChart.HorizontalAxis>
            <telerik:CategoricalAxis LabelStyle="{StaticResource LabelStyle}" />
        </telerik:RadCartesianChart.HorizontalAxis>
        <telerik:RadCartesianChart.VerticalAxis>
            <telerik:LinearAxis LabelStyle="{StaticResource LabelStyle}" />
        </telerik:RadCartesianChart.VerticalAxis>
    </telerik:RadCartesianChart>
</Grid>

Hope this helps.


All the best,
Giuseppe
the Telerik team

[Denis]

Thx for the solution.