WPF graph:graph.Plots.Clear() error

[lizi]

Hi,

I need to dynamically add plot to graph.The code as follows,

ObservableCollection<Point[]> dataSource = new ObservableCollection<Point[]>();

graph.DataSource = dataSource ;

public void AddOnePlot(Point[] pointData)

{

     Plot plot = new Plot();

     graph.Plots.Add(plot);

     dataSource.Add(pointData);

}

But when I call graph.Plots.Clear(),the error is"Range action are not supported.".How I clear all plots in graph?

Look forward to your reply.Thanks.

[lizi]

I have found a solution.

for(int i = graph.Plots.Count;i>=0;i--)

{

    graph.Plots.RemoveAt(i);

}

This workaround is no problem.But for the graph.Plots.Clear() function,I don't know why it wrong.

Still hope your answer!

[lizi]

I have found a solution.

for(int i = graph.Plots.Count;i>=0;i--)

{

    graph.Plots.RemoveAt(i);

}

This workaround is no problem.But for the graph.Plots.Clear() function,I don't know why it wrong.

Still hope your answer!

[phansen · Accepted solution]

The Plots collection on the Graph class derives from NotifyingCollection, which raises a single optimized aggregate event when multiple items change. The .NET ObservableCollection on the other hand raises separate events for every modified item in the collection. The Measurement Studio controls support both models, but WPF controls like ItemsControl do not support aggregate events (the "range actions" in the error message).

However, there is a bug in the current version of the Legend control: if you bind the ItemsSource property to a collection instead of to a graph, you may see this error if a default collection view gets created. To prevent this, you can serialize events (as you showed above, removing individual items instead of clearing), or you can use the NotifyCollectionChangedSimplifier to adapt the optimized collection to the "separate event for every item" model:

    xmlns:ni="http://schemas.ni.com/controls/2009/xaml/presentation"
    xmlns:niPrimitives="http://schemas.ni.com/controls/2009/xaml/presentation/primitives"

    ...

    <Grid.Resources>
        <niPrimitives:NotifyCollectionChangedSimplifier x:Key="CollectionSimplifier" />
    </Grid.Resources>

    ...

    <ni:Legend ItemsSource="{Binding Plots, ElementName=graph, Converter={StaticResource CollectionSimplifier}}" />

[lizi]

Thank you.It is very helpful to me.

[phansen]

Just wanted to let you know this issue was fixed in the Measurement Studio 2015 release.