在WPF應用程序上使用oxyplot在圖形上畫點

Question

在我的項目中，每當圖形等於某個值時，我都希望在實時圖形上繪制一個點。 我不知道該怎么做。 這是我用來顯示實時圖形的代碼：

 public class MainViewModel
{
    public PlotModel DataPlot { get; set; }        
    public DispatcherTimer graphTimer;
    private double _xValue = 10;

    public MainViewModel()
    {
        DataPlot = new PlotModel();
        DataPlot.Series.Add(new LineSeries());

        graphTimer = new DispatcherTimer();
        graphTimer.Interval = TimeSpan.FromMilliseconds(MainWindow.timerRefreshMs);
        graphTimer.Tick += dispatcherTimer_Tick;
        graphTimer.Start();    

    }        

    public void dispatcherTimer_Tick(object sender, EventArgs e)
    {
        ScatterSeries series = new ScatterSeries();
        Dispatcher.CurrentDispatcher.Invoke(() =>
        {
            (DataPlot.Series[0] as LineSeries).Points.Add(new DataPoint(_xValue, MainWindow.z));     
            //DataPlot.InvalidatePlot(true);
            //_xValue++;
            if(MainWindow.z == 900)
            {
              //ADD A POINT  

            }
            DataPlot.InvalidatePlot(true);

            _xValue++;

            if ((DataPlot.Series[0] as LineSeries).Points.Count > 80) //show only 10 last points
                (DataPlot.Series[0] as LineSeries).Points.RemoveAt(0); //remove first point
        });
    }


}

Answer 1

您應該使用以下模式來添加或刪除數據：

    int _xValue = 0;
    public void dispatcherTimer_Tick(object sender, EventArgs e)
    { 
        Dispatcher.CurrentDispatcher.Invoke(() =>
        {
            LineSeries ser = plotModel.Series[0] as LineSeries;
            if (ser != null)
            {
                // check your conditions and caclulate the Y value of the point
                double yValue = 1;
                ser.Points.Add(new DataPoint(_xValue, yValue));
                _xValue++;
            } 
            if (ser.Points.Count > 80) //show only 10 last points
                ser.Points.RemoveAt(0); //remove first point
            plotModel.InvalidatePlot(true);
        });
    }

讓我知道是否有任何問題。