Question

//网格线不会随着线点的变化而移动。我应该添加什么代码才能使它看起来像cpu性能图表？

    Series test1 = new Series();
    Series test2 = new Series();

    private void Form1_Load(object sender, EventArgs e)
    {        
        test1.Color = Color.Blue;
        test1.ChartType = SeriesChartType.FastLine;
        test1.BorderWidth = 2;

        test2.Color = Color.Red;
        test2.ChartType = SeriesChartType.FastLine;
        test2.BorderWidth = 2;

        chart1.Series.Add(test1);
        chart1.Series.Add(test2);

        chart1.ChartAreas[0].AxisX.MajorGrid.Enabled = true;
        chart1.ChartAreas[0].AxisX.IsStartedFromZero = true;
        chart1.ChartAreas[0].AxisX.IntervalOffsetType = DateTimeIntervalType.Number;         
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        Axis xaxis = chart1.ChartAreas[0].AxisX;
        xaxis.Minimum = xaxis.Maximum - 10;
        Random rnd = new Random();
        int dice = rnd.Next(1, 7); 
        float num1 = rnd.Next(1, 13);
        test1.Points.Add(num1);
        test2.Points.Add(dice);
        chart1.ResetAutoValues();
    }

Answer 1

您有两种选择：

您可以从头开始删除最旧的DataPoints，一旦您有多个点数，就可以开始。
您可以设置X轴的最小值和最大值来控制显示的范围。

如果您要快速或长时间添加DataPoints，前一个选项是您最终需要执行的操作。

您可能还想使用缩放来回顾过去。如果您需要保留数据，您仍然可以将删除的点添加到内存中的列表中，并在需要时将其恢复。

Answer 2

您可以使用Grid.IntervalOffset属性：

int GridlinesOffset = 0;

// ...

// In chart update loop:

// Make gridlines move.
chart.ChartAreas[0].AxisX.MajorGrid.IntervalOffset = -GridlinesOffset;

// Calculate next offset.
GridlinesOffset++;
GridlinesOffset %= (int) chart.ChartAreas[0].AxisX.MajorGrid.Interval;

在以下示例中查看timer_Tick()方法。

using System;
using System.Drawing;
using System.Windows.Forms;

namespace CPUPerformanceChart
{
    public partial class Form1 : Form
    {
        private int GridlinesOffset = 0;

        public Form1()
        {
            InitializeComponent();

            Color axisColor = Color.FromArgb(100, 100, 100);
            Color gridColor = Color.FromArgb(200, 200, 200);
            Color backColor = Color.FromArgb(246, 246, 246);
            Color lineColor = Color.FromArgb(50, 50, 200);

            chart.Series[0].Color = lineColor;

            chart.ChartAreas[0].BackColor = backColor;

            chart.ChartAreas[0].BorderWidth = 1;
            chart.ChartAreas[0].BorderColor = axisColor;
            chart.ChartAreas[0].BorderDashStyle =
                System.Windows.Forms.DataVisualization.Charting.ChartDashStyle.Solid;

            chart.ChartAreas[0].AxisX.LineColor = axisColor;
            chart.ChartAreas[0].AxisY.LineColor = axisColor;

            chart.ChartAreas[0].AxisX.MajorGrid.LineColor = gridColor;
            chart.ChartAreas[0].AxisY.MajorGrid.LineColor = gridColor;

            chart.ChartAreas[0].AxisX.MajorGrid.Interval = 10;
            chart.ChartAreas[0].AxisY.MajorGrid.Interval = 10;

            // 60 seconds interval.
            chart.ChartAreas[0].AxisX.Minimum = 0;
            chart.ChartAreas[0].AxisX.Maximum = 60;

            chart.ChartAreas[0].AxisY.Minimum = 0;
            chart.ChartAreas[0].AxisY.Maximum = 100;

            chart.ChartAreas[0].AxisX.LabelStyle.Enabled = false;
            chart.ChartAreas[0].AxisY.LabelStyle.Enabled = false;

            chart.ChartAreas[0].AxisX.MajorTickMark.Enabled = false;
            chart.ChartAreas[0].AxisY.MajorTickMark.Enabled = false;

            for (int i = 0; i < 60; i++)
            {
                chart.Series["Series1"].Points.AddY(0);
            }
        }

        // timer.Interval = 1000.
        private void timer_Tick(object sender, EventArgs e)
        {
            float nextValue = cpuPerformanceCounter.NextValue();

            labelCpuUsage.Text = String.Format("{0:0.00} %", nextValue);

            chart.Series["Series1"].Points.AddY(nextValue);
            chart.Series["Series1"].Points.RemoveAt(0);

            // Make gridlines move.
            chart.ChartAreas[0].AxisX.MajorGrid.IntervalOffset = -GridlinesOffset;

            // Calculate next offset.
            GridlinesOffset++;
            GridlinesOffset %= (int) chart.ChartAreas[0].AxisX.MajorGrid.Interval;
        }
    }
}

结果是：

CPU Performance Chart

如果在图表上添加数据，如何在图表上移动x轴网格

2 个答案: