如何访问图表以在 c# 中添加数据点

Question

I am trying to write a class to update chart data. I have created the chart through windows forms which has autogenerated the code in Form1.cs and Form1.Designer.cs

Here is what i think is the relevant part from Form1.designer.cs:

private void InitializeComponent()
{
    System.Windows.Forms.DataVisualization.Charting.ChartArea chartArea1 = new System.Windows.Forms.DataVisualization.Charting.ChartArea();
    System.Windows.Forms.DataVisualization.Charting.Legend legend1 = new System.Windows.Forms.DataVisualization.Charting.Legend();
    System.Windows.Forms.DataVisualization.Charting.Series series1 = new System.Windows.Forms.DataVisualization.Charting.Series();
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint1 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 2D);
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint2 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 3D);
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint3 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 2D);
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint4 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 25D);
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint5 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 2D);
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint6 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 3D);
    System.Windows.Forms.DataVisualization.Charting.DataPoint dataPoint7 = new System.Windows.Forms.DataVisualization.Charting.DataPoint(0D, 0D);
    this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
    this.chart1 = new System.Windows.Forms.DataVisualization.Charting.Chart();
    this.tableLayoutPanel1.SuspendLayout();
    ((System.ComponentModel.ISupportInitialize)(this.chart1)).BeginInit();
    this.SuspendLayout();

I have written another class called UpdateGraph.cs which has a method to add an extra point to the graph

namespace DataLogger
{
    class UpdateGraph
    {
        public void addGraphPoints()
        {
            chart1.Series.Points.AddXY(0, 10);   
        }
    }
}

The problem is I get an error with message

The name chart1 does not exist in the current context

So if anyone could explain how I can access the chart to modify the data (or what i should be refering to) I would really appreciate it as I am a bit stumped at the moment.

Answer 1

You could try this one:

using System.Windows.Forms.DataVisualization.Charting;

class UpdateGraph
{
    public Chart Chart1 { get; set; }

    public UpdateGRaph(Chart chart)
    {
        Chart1 = chart;
    }

    public void AddGraphPoints()
    {
        Chart1.Series.Points.AddXY(0, 10);

    }
}

Answer 2

Forms Designer will create a local chart in InitializeComponent() - maybe there's a way to prevent it but I've yet to find it. The trick is to get the chart out of your control hierarchy. For example, my chart in Designer.cs is added to grpStuff:

this.grpStuff.Controls.Add(chrtStuff);

and its name can be found in Designer.cs also:

chrtStuff.Name = "chartName";

SO - in my code I find the chart by:

chrt = (System.Windows.Forms.DataVisualization.Charting.Chart)grpStuff.Controls("chartName");

Answer 3

chart1.Series["Your series name"].Points.AddXY(0, 10); sorry to be being this fast