OxyPlot not refreshing in VB.net - wpf

Question

I was using Visual Studio to chart data when I ran into a problem with the logarithmic X-Axis. I have now turned to OxyPlot, however, I am running into huge issues with getting my data to populate. I switched from the windows forms to WPF, so this could be a XAML issue with binding (unsure). Essentially I took their very limited example in VB.net and can easily reproduce it. What I am struggling with is reproducing dynamic plotting with OxyPlot. Here is my code so far:
Sample: (http://docs.oxyplot.org/en/latest/getting-started/hello-wpf-vb.html)
Public Sub New()
Model = New PlotModel()
Model.Title = "Simple example"
Model.Subtitle = "using OxyPlot in VB.NET"
Dim series1 = New LineSeries()
series1.Title = "Series 1"
series1.MarkerType = MarkerType.Circle
series1.Points.Add(New DataPoint(0, 0))
series1.Points.Add(New DataPoint(10, 18))
series1.Points.Add(New DataPoint(20, 12))
series1.Points.Add(New DataPoint(30, 8))
series1.Points.Add(New DataPoint(40, 15))
Dim series2 = New LineSeries()
series2.Title = "Series 2"
series2.MarkerType = MarkerType.Square
series2.Points.Add(New DataPoint(0, 4))
series2.Points.Add(New DataPoint(10, 12))
series2.Points.Add(New DataPoint(20, 16))
series2.Points.Add(New DataPoint(30, 25))
series2.Points.Add(New DataPoint(40, 5))
Model.Series.Add(series1)
Model.Series.Add(series2)
End Sub
Then I attempt to add more data to simulate dynamically loading data. I also am aware that I must use invalidate() and that Update() is deprecated. I added a button to the form and give it another series to add to the chart upon click.
Button Click:
Private Sub test_Click(sender As Object, e As RoutedEventArgs) Handles test.Click
Dim series3 = New LineSeries()
series3.Title = "Series 3"
series3.MarkerType = MarkerType.Square
series3.Points.Add(New DataPoint(20, 20))
series3.Points.Add(New DataPoint(21, 21))
series3.Points.Add(New DataPoint(22, 22))
series3.Points.Add(New DataPoint(23, 23))
series3.Points.Add(New DataPoint(24, 24))
Model.Series.Add(series3)
Model.InvalidatePlot(True)
End Sub
Here is also their lovely reference to updating their dataPlot: http://docs.oxyplot.org/en/latest/common-tasks/refresh-plot.html#examples

Answer 1

In your event handler, you need to add series3 to your Model before calling InvalidatePlot i.e.
Model.Series.Add(series3);
Model.InvalidatePlot(true);
Update
Also, you need to make sure your PlotModel notifies the view (XAML) of your changes. If I use the example from Oxyplot documentation as an example (the one you specified), I'd modify the code as such:
Public Class MainViewModel Implements INotifyPropertyChanged
Private mmodel As PlotModel
Public Event PropertyChanged As PropertyChangedEventHandler _
Implements INotifyPropertyChanged.PropertyChanged
Public Sub New()
Model = New PlotModel()
Model.Title = "Simple example"
Model.Subtitle = "using OxyPlot in VB.NET"
Dim series1 = New LineSeries()
series1.Title="Series 1"
series1.MarkerType = MarkerType.Circle
series1.Points.Add(New DataPoint(0, 0))
series1.Points.Add(New DataPoint(10, 18))
series1.Points.Add(New DataPoint(20, 12))
series1.Points.Add(New DataPoint(30, 8))
series1.Points.Add(New DataPoint(40, 15))
Dim series2 = New LineSeries()
series2.Title="Series 2"
series2.MarkerType = MarkerType.Square
series2.Points.Add(New DataPoint(0, 4))
series2.Points.Add(New DataPoint(10, 12))
series2.Points.Add(New DataPoint(20, 16))
series2.Points.Add(New DataPoint(30, 25))
series2.Points.Add(New DataPoint(40, 5))
Model.Series.Add(series1)
Model.Series.Add(series2)
End Sub
Property Model() As PlotModel
Get
Return mmodel
End Get
Set(value As PlotModel)
mmodel = value
NotifyPropertyChanged("Model")
End Set
End Property
Private Sub test_Click(sender As Object, e As RoutedEventArgs) Handles test.Click
Dim series3 = New LineSeries()
series3.Title = "Series 3"
series3.MarkerType = MarkerType.Square
series3.Points.Add(New DataPoint(20, 20))
series3.Points.Add(New DataPoint(21, 21))
series3.Points.Add(New DataPoint(22, 22))
series3.Points.Add(New DataPoint(23, 23))
series3.Points.Add(New DataPoint(24, 24))
Model.Series.Add(series3)
Model.InvalidatePlot(True)
End Sub
End Class