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我是 C# 编程的新手，正在尝试编写一个应用程序，这是我的期末论文的一部分。

我有一个微处理器，它通过串行端口不断地将数据从传感器发送到我的计算机。我想要的只是使用 Zedgraph 绘制这些数据。

问题是图表有太多的延迟和时间滞后。似乎问题的发生是因为我以非常高的速率不断更新整个图表。我在一周内一直在解决这个问题，但仍然没有找到解决方案。如果有人可以帮助我，我会非常高兴。

这是我的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using ZedGraph;
using System.IO.Ports;
using System.Threading;

namespace DynamicData
{
public partial class Form1 : Form
{
    private SerialPort port;
    private string buffer = "";

    private void connect()
    {
        port = new SerialPort("COM8", 115200, Parity.None, 8, StopBits.One);
        port.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(port_DataReceived);
        if (!port.IsOpen) port.Open();
    }

    public Form1()
    {
        InitializeComponent();
    }


    private void Form1_Load( object sender, EventArgs e )
    {
        connect();
        GraphPane myPane = zedGraphControl1.GraphPane;          
        RollingPointPairList list = new RollingPointPairList(500);
        LineItem curve = myPane.AddCurve( "Sensor", list, Color.Blue, SymbolType.None );

        myPane.XAxis.Scale.Min = 0;
        myPane.XAxis.Scale.Max = 10;
        myPane.YAxis.Scale.Min = 0;
        myPane.YAxis.Scale.Max = 300;
        myPane.XAxis.Scale.MinorStep = 0.5;
        myPane.XAxis.Scale.MajorStep = 1;

        zedGraphControl1.AxisChange();

    }


    private void port_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
    {
        //sample data: ;100*100000:
        //sampling rate ~100Hz
        buffer += port.ReadExisting();

        //flush incomplete package
        while (buffer[0] != ';')
        {
            buffer = buffer.Remove(0, 1);
            if (buffer.Length < 1) break;
        }

        //got a complete package, go to data handling
        while (buffer.Contains(":"))
        {
            DataHandling();
        }
    }


    private void DataHandling()
    {
        string[] nameArray = buffer.Split(new[] { ";", ":", "*" }, StringSplitOptions.RemoveEmptyEntries);

        //plot sensor data vs. time
        draw(Convert.ToInt32(nameArray[0]), Convert.ToInt32(nameArray[1]));

        //remove handled package in buffer
        var index = buffer.IndexOf(":");
        buffer = buffer.Remove(0, index + 1);

    }

    double time = 0;
    private void draw(int sensor, int t)
    {
        //convert tick to sec (uP clock rate = 16MHZ)
        time = time + (t / 16000000.0);

        // Get the first CurveItem in the graph
        LineItem curve = zedGraphControl1.GraphPane.CurveList[0] as LineItem;

        // Get the PointPairList
        IPointListEdit list = curve.Points as IPointListEdit;
        list.Add(time, sensor);


        //Keep the X scale at a rolling 10 second interval, with one
        //major step between the max X value and the end of the axis
        Scale xScale = zedGraphControl1.GraphPane.XAxis.Scale;
        if (time > xScale.Max - xScale.MajorStep)
        {
            xScale.Max = time + xScale.MajorStep;
            xScale.Min = xScale.Max - 10.0;
        }

        //Display sensor data
        this.Invoke(new Action(() => { textBox1.Text = byte1.ToString(); }));

        axisChangeZedGraph(zedGraphControl1);

    }

    delegate void axisChangeZedGraphCallBack(ZedGraphControl zg);
    private void axisChangeZedGraph(ZedGraphControl zg)
    {
        if (zg.InvokeRequired)
        {
            axisChangeZedGraphCallBack ad = new axisChangeZedGraphCallBack(axisChangeZedGraph);
            zg.Invoke(ad, new object[] { zg });
        }
        else
        {
          //  zg.AxisChange();
            zg.Invalidate();
            zg.Refresh();
        }
    }

}
}

感谢您的阅读！

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2 回答 2

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问题是你invalidate每画一个点就打电话。这会产生非常高的处理器负载。我正在做一个非常相似的项目，USB 设备，实时绘图数据。我使用单独的线程进行数据采集。该线程每次收到数据包时都会创建一个事件。数据被放入队列中。图表使用计时器进行更新。你可以在这里找到一个例子。在此代码中，图形每 50 毫秒更新一次，实际上并不需要更快地绘制。在计时器中，我检查队列的大小并绘制或多或少的点，然后调用invalidate. 我不知道这是否是一个好的解决方案（只有 6 个月的 C# 经验），但它在 7500 分的情况下效果很好。您应该首先尝试使用计时器来刷新图形。

于 2013-06-03T08:43:40.183 回答
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1）。只创建和格式化曲线一次。将其存储在模块级别。

2）。添加点时使用curve.AddPoint();thenzg.Refresh();

//this is just to add a point to the plot, the curve object should have already been created
private void draw(int sensor, int t)
    {
        //convert tick to sec (uP clock rate = 16MHZ)
        time = time + (t / 16000000.0);

        //curve should be a module-level variable already set up with proper formatting,
        //just no points yet
        curve.AddPoint(time, sensor);

        //Display sensor data
        this.Invoke(new Action(() => { textBox1.Text = byte1.ToString(); }));

        zg.AxisChange();
        zg.Refresh();

    }
于 2014-12-22T00:29:35.473 回答