How do I correctly update my chart values? (In real time)

Question

I recently encountered a tool called LiveChart and decided to test it out.

Unfortunately I\'ve been having some problems figuring out how to update the chart values

Answer 1

Live-Charts tries to keep it simple. The logic is to use a generic collection with the type you need to plot, and then as easy as adding/removing or updating any element in this collection then your chart will be updated.

To answer your question, you normally need to:

public partial class Form1 : Form
{
    private ObservableValue value1;

    public Form1()
    {
        InitializeComponent();

        //int val1 = int.Parse(Settings.Default.Value1);

        value1 = new ObservableValue(3);
        //...

        cartesianChart1.Series.Add(new LineSeries 
        {
            Values = new ChartValues<ObservableValue> { value1, ... },
        });
    }

    private void changeValue1ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        value1.Value = 10;
        Settings.Default.Value1 = "10";
        Settings.Default.Save();
        this.Text = Settings.Default.Value1;

    }
}

Then the library will handle animations and the update

Answer 2

Hi for Pie chart you can upload the value in this easy way:

code Behind:

/// <summary>
/// Interaction logic for StatusChart.xaml
/// </summary>
public partial class StatusChart : UserControl
{
    #region - Values -
    private List<Double> values;
    public List<Double> Values
    {
         
        get => values;
        set
        {
            if (value is null) throw new NullReferenceException();
            if (value.Count > PieChart.Series.Count) throw new IndexOutOfRangeException();

            for(int serie = 0; serie < PieChart.Series.Count; serie++)
            {
                PieChart.Series[serie].ActualValues[0] = values[serie];
            }

            PieChart.Series.ForEach((i, s) => s.ActualValues[0] = value[i]);
        }
    }
    #endregion
    public StatusChart()
    {
        InitializeComponent();
        
        values = Enumerable.Repeat(1D, PieChart.Series.Count).ToList();
        
        PointLabel = chartPoint => string.Format(new CultureInfo("en-US"), "{0:#0}s", chartPoint.Y);

        GridRoot.DataContext = this;
    }
    public Func<ChartPoint, string> PointLabel { get; set; }

    /// <summary>
    /// method to enalrge the slice (part of pie chart) 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="chartpoint"></param>
    private void Chart_OnDataClick(object sender, ChartPoint chartpoint)
    {
        var chart = (LiveCharts.Wpf.PieChart)chartpoint.ChartView;

        //clear selected slice.
        foreach (PieSeries series in chart.Series)
            series.PushOut = 0;

        var selectedSeries = (PieSeries)chartpoint.SeriesView;
        selectedSeries.PushOut = 7;
    }             
}

and xaml code:

<UserControl x:Class="StatusChart"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:lvc="clr-namespace:LiveCharts.Wpf;assembly=LiveCharts.Wpf"
         mc:Ignorable="d" 
         d:DesignHeight="300" d:DesignWidth="500"
         d:DataContext="{d:DesignInstance local:StatusChart}">

<Grid x:Name="GridRoot">
    <lvc:PieChart x:Name="PieChart" LegendLocation="Bottom" DataClick="Chart_OnDataClick" Hoverable="False"><!-- DataTooltip="{x:Null}">-->
        <lvc:PieChart.Series>
            
            <lvc:PieSeries Title="serie1" 
                           Values="1" DataLabels="True" LabelPoint="{Binding PointLabel}">
            </lvc:PieSeries>

            <lvc:PieSeries Title="serie2" 
                           Values="1" DataLabels="True" LabelPoint="{Binding PointLabel}">
            </lvc:PieSeries>

            <lvc:PieSeries Title="serie3" Values="1" DataLabels="True" 
                           LabelPoint="{Binding PointLabel}"/>

            <lvc:PieSeries Title="serie4" Values="1" DataLabels="True" 
                           LabelPoint="{Binding PointLabel}">
            </lvc:PieSeries>

            <lvc:PieSeries Title="serie4" Values="1" DataLabels="True" 
                           LabelPoint="{Binding PointLabel}">
            </lvc:PieSeries>
        </lvc:PieChart.Series>            
    </lvc:PieChart>
</Grid>

and just to try the control in a window wpf test put this few lines:

 var temporalSc = Enumerable.Repeat(1D, StatusChart.PieChart.Series.Count).ToList();
            for (var i = 0; i < StatusChart.PieChart.Series.Count; i++)
            {
                temporalSc[i] += rnd.Next(1, 87);
            }

            StatusChart.Values.Clear();
            StatusChart.Values = temporalSc;

Answer 3

Note: The question is about LiveCharts. But this answer is posted based on MSChart. To see the answer about LiveCharts see other answer.

Chart supports data-binding. Use data-binding and update data source then refresh chart. For example:

DataTable table = new DataTable();
Random random = new Random();
private void Form1_Load(object sender, EventArgs e)
{
    table.Columns.Add("X", typeof(int));
    table.Columns.Add("Y", typeof(int));
    for (int i = 0; i < 10; i++)
        table.Rows.Add(i+1, random.Next(100));
    chart1.Series[0].ChartType = 
        System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Column;
    chart1.Series[0].XValueMember = "X";
    chart1.Series[0].YValueMembers = "Y";
    chart1.DataSource = table;
    chart1.ChartAreas[0].AxisX.Interval = 1;
    chart1.ChartAreas[0].AxisX.Minimum = 0;
    chart1.ChartAreas[0].AxisX.Maximum = 10;
    chart1.ChartAreas[0].AxisY.Interval = 10;
    chart1.ChartAreas[0].AxisY.Minimum = 0;
    chart1.ChartAreas[0].AxisY.Maximum = 100;
    chart1.DataBind();
    var timer = new Timer() { Interval= 300};
    timer.Tick += timer_Tick;
    timer.Start();
}
void timer_Tick(object sender, EventArgs e)
{
    for (int i = 0; i < 10; i++)
        table.Rows[i][1]= random.Next(100);
    chart1.DataBind();
}