Dynamic Data Display WPF Binding in MVVM pattern

Question

So, I'd like to bind the data source of a LineGraph to a CompositeDataSource in a wpf app with MVVM pattern. Here is what I've done so far:

The relevant line in the XAML:

<d3:LineGraph DataSource="{Binding signal}" Stroke="Blue"/>

signal is my CompositeDataSource object.

Relevant part of my ViewModel:

private void LoadSignalExecuted()
    {
        OnLoadSignal();

        plotter.CreateGraph(dataFile);
        signal = plotter.ECGData;

        OnPropertyChanged("signal");
    }

OnLoadSignal() does nothing important in this case. plotter is a class in my Model namespace. The CreateGraph(dataFile) does nothing else but populates a

public List<Points> Values { get; private set; }

object. It's populated correctly, I checked. My Points class is the following:

class Points
{

    public Double X { get; set; }
    public Double Y { get; set; }

    public Points(Double xData, Double yData)
    {
        X = xData;
        Y = yData;
    }

} 

plotter.ECGData looks like this:

public CompositeDataSource ECGData
    {
        get
        {

                var xData = new EnumerableDataSource<double>(Values.Select(v => v.X));
                xData.SetXMapping(x => x);
                var yData = new EnumerableDataSource<double>(Values.Select(v => v.Y));
                yData.SetYMapping(y => y);
                _data = xData.Join(yData);

                return _data;
        }
    }

Where _data is a CompositeDataSource of course.

I figured this would work but the LineGraph doesn't appear upon OnPropertyChanged("signal"), which is implemented correctly I'm positive about that. VS Output Box says:

System.Windows.Data Error: 40 : BindingExpression path error: 'signal' property not found on 'object' ''ECGViewModel' (HashCode=41182536)'. BindingExpression:Path=signal; DataItem='ECGViewModel' (HashCode=41182536); target element is 'LineGraph' (Name=''); target property is 'DataSource' (type 'IPointDataSource')

Can someone point out the mistake here? Thanks!

Answer 1

Is ECGViewModel in a different project? Have you tried a full rebuild? Perhaps you have an old version of ECGViewModel around that actually doesn't have the signal property on it.