Hi Petar, thanks for your reply, and for passing my issue on to the developers. When you say "unless you toggle two different providers in your app", you can't do that and have both sets show on the graph at the same time, can you?
I've come up with minimal example of my issues for your reference:
MainWindow.xaml:
<Window x:Class="TwoDynamic.MainWindow"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<ResourceDictionary>
<DataTemplate x:Key="PointDataTemplate">
<Ellipse Width="4" Height="4" Fill="Red"/>
</DataTemplate>
</ResourceDictionary>
</Window.Resources>
<Grid>
<telerik:RadCartesianChart>
<telerik:RadCartesianChart.Resources>
<Style TargetType="telerik:LineSeries">
<Setter Property="StrokeThickness" Value="2"/>
<Setter Property="Stroke" Value="Blue" />
</Style>
<Style TargetType="telerik:BarSeries">
<Setter Property="PointTemplate" Value="{StaticResource PointDataTemplate}" />
<Setter Property="CombineMode" Value="None"/>
</Style>
</telerik:RadCartesianChart.Resources>
<telerik:RadCartesianChart.Grid>
<telerik:CartesianChartGrid MajorLinesVisibility="XY" />
</telerik:RadCartesianChart.Grid>
<telerik:RadCartesianChart.HorizontalAxis>
<telerik:DateTimeContinuousAxis LabelFitMode="Rotate" LabelFormat="MMM-dd" />
</telerik:RadCartesianChart.HorizontalAxis>
<telerik:RadCartesianChart.VerticalAxis>
<telerik:LinearAxis/>
</telerik:RadCartesianChart.VerticalAxis>
<telerik:RadCartesianChart.SeriesProvider>
<telerik:ChartSeriesProvider Source="{Binding Path=Series}">
<telerik:ChartSeriesProvider.SeriesDescriptors>
<telerik:CategoricalSeriesDescriptor ItemsSourcePath="Data" TypePath="SeriesType" CategoryPath="Date" ValuePath="Value"/>
</telerik:ChartSeriesProvider.SeriesDescriptors>
</telerik:ChartSeriesProvider>
</telerik:RadCartesianChart.SeriesProvider>
</telerik:RadCartesianChart>
</Grid>
</Window>
MainWindow.xaml.cs:
And ViewModel.cs:
using System;
using System.Collections.ObjectModel;
using Telerik.Windows.Controls.ChartView; // Should not have this in VM layer!
namespace TwoDynamic
{
public class DataPoint
{
public DateTime Date { get; set; }
public double Value {get;set;}
}
public abstract class SeriesBase
{
public abstract ObservableCollection<DataPoint> Data { get; set; }
// This DOES NOT BELONG in the ViewModel! TypePath really needs
// a converter so this can provide a generic type, and have the
// Telerik-specific type supplied in the View layer.
public abstract Type SeriesType { get; }
}
public class PointData: SeriesBase
{
public override Type SeriesType { get { return typeof(BarSeries); } }
public override ObservableCollection<DataPoint> Data { get; set; }
}
public class LineData : SeriesBase
{
public override Type SeriesType { get { return typeof(LineSeries); } }
public override ObservableCollection<DataPoint> Data { get; set; }
}
public class ViewModel
{
private Random _Random;
private ObservableCollection<SeriesBase> _Series;
public ObservableCollection<SeriesBase> Series { get { return _Series; } }
public ViewModel()
{
_Random = new Random();
_Series = new ObservableCollection<SeriesBase>();
// In reality there would be a variable number of these.
_Series.Add(new PointData() { Data = GenerateSomeData() });
_Series.Add(new PointData() { Data = GenerateSomeData() });
// I can either add PointData items, or LineData items, but not both
//_Series.Add(new LineData() { Data = GenerateSomeData() });
//_Series.Add(new LineData() { Data = GenerateSomeData() });
}
private ObservableCollection<DataPoint> GenerateSomeData()
{
ObservableCollection<DataPoint> newCollection = new ObservableCollection<DataPoint>();
for (int i = 0; i < 10; i++)
newCollection.Add(new DataPoint() { Date = new DateTime(2012, 12, 31).AddDays(i), Value = _Random.Next(100) });
return newCollection;
}
}
}
My problem #1 is that in ViewModel, I can add any number of EITHER LineData OR PointData items to the list and it all works fine. However, even though they're both SeriesBase types which is what is exposed in the collection, if I add both it throws the exception:
My real LineData and PointData classes are of course much more complicated, and have lots of distinct functionality relevant to the actual data that is being displayed. I have worked around this by creating an adapter class that can hold either of these types of objects, and whose properties return the contained object's values, but this is a pretty ugly hack.
The second issue I think you already understand, and that is that there should be no references to Telerik types in the ViewModel, but there's no (clean) way to use the TypePath setting without doing so (thus the need for the converter).
Does that clear things up?
Thanks,
Louis