绑定OxyPlot Tracker并在TextBlock中设置获取值

Question

Project - WPF, C#, IDE - Visual Studio. I want bind value traking on my PlotView . My code XAML:

 <Border CornerRadius="6" BorderBrush="Gray" BorderThickness="4" Grid.Column="0" Grid.ColumnSpan="2">
        <oxy:PlotView Background="White" Model="{Binding GraphicModel.Model}"  >

        </oxy:PlotView>
    </Border>

    <TextBlock Text="{Binding CurrentTrackerValue}" Grid.Column="0" Grid.Row="1"/>

I know, what PlotView.Model have event TrackerChange . How using this event? PS: I use pattern MVVM, so i want using command instead event. Thank!

Answer 1

If I understand your requirement correctly, you want to update a TextBlock each time the Tracker is updated. I believe you were right on track with the TrackerChanged event. You could do the following in your ViewModel, where you are creating the PlotModel instance, which would be bound to the OxyPlot Graph

PlotModelName.TrackerChanged += (sender, eventArgs)=>
{
  CurrentTrackerValue = eventArgs.HitResult != null ? eventArgs.HitResult.Text : CurrentTrackerValue;
  NotifyPropertyChanged(nameof(CurrentTrackerValue));
};

Where CurrentTrackerValue is defined as

public string CurrentTrackerValue { get; set; }

This would ensure the CurrentTrackerValue property is updated each time Tracker is changed via the TrackerChangedEvent

Answer 2

guys thanks it works steps bellow :)

.NET 4.7.2

1. I added INotifyPropertyChanged and

public string CurrentTrackerValueX { get; set; }
      public string CurrentTrackerValueY { get; set; }

2. then generate

protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) 
    { 
    PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); 
    }

3. then i follow your idea

pm.TrackerChanged += (sender, eventArgs) =>
    {
        string CurrentTrackerValue = "";
        CurrentTrackerValue = eventArgs.HitResult != null ? eventArgs.HitResult.Text : CurrentTrackerValue;
        if (!String.IsNullOrEmpty(CurrentTrackerValue))
        {
            var x = Regex.Matches(CurrentTrackerValue, "([0-9]*,[0-9]*)");
            CurrentTrackerValueX = x[0].Value;
            CurrentTrackerValueY = x[1].Value;
            OnPropertyChanged(nameof(CurrentTrackerValueX));
            OnPropertyChanged(nameof(CurrentTrackerValueY));
        }
    };

If loop is needed cause of null value in textbox after leaving Tracker, he still want gives null to textbox.

All done and works with this type of string :)

editcurrentLineSeries[i].TrackerFormatString = "{0}\n{1}: {2:0.00}\n{3}: {4:0.00}";