C# と VB.NET の質問掲示板

■No79089 (さくらとあおい さん) に返信

こんな感じ？
「参照設定」に、System.Windows.Forms.DataVisualization を追加。
Form の上に FlowLayoutPanel と Chart を置く。
FlowLayoutPanel の上に Button を置く。
「開始する」をクリックすると、スクロールが始まる。
要は、「新しいデータを最後に追加し、最初のデータを削除する」ってこと。
「データを更新する」と「描画する」を別スレッドにしたので、「描画中にデータが更新される」ことを防ぐ必要が出てきてしまった。

using System;
using System.Data;
using System.Windows.Forms;

namespace Wankuma79058
{
    public partial class Form1 : Form
    {
        private System.Threading.Timer dataTimer;
        private System.Threading.Timer drawTimer;
        private System.Threading.SpinLock locker;
        private DataTable dataTable;
        private int additionalTime;
        private Action drawAction;

        public Form1()
        {
            InitializeComponent();
            this.flowLayoutPanel1.Dock = DockStyle.Bottom;
            this.flowLayoutPanel1.AutoSize = true;
            this.chart1.Dock = DockStyle.Fill;
            this.button1.Text = "開始する";
            this.button1.Click += this.StartTimer;
            this.FormClosing += new FormClosingEventHandler(FormClosingHandler);

            this.additionalTime = 0;
            this.drawAction = new Action(this.drawGraph);
            this.locker = new System.Threading.SpinLock();

            this.dataTable = new DataTable();
            this.dataTable.Columns.Add("time", typeof(int));
            this.dataTable.Columns.Add("data", typeof(float));
            for (int i = 0; i < 20; ++i)
            {
                var row = this.dataTable.NewRow();
                row["time"] = (++this.additionalTime);
                row["data"] = 0;
                this.dataTable.Rows.Add(row);

            }

            this.chart1.Series.Clear();
            var data = this.chart1.Series.Add("data");
            data.ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.SplineArea;
            data.XValueMember = "time";
            data.YValueMembers = "data";
            this.chart1.DataSource = this.dataTable;

            this.dataTimer = new System.Threading.Timer(this.DataTimerCallback, null, System.Threading.Timeout.Infinite, 200);
            this.drawTimer = new System.Threading.Timer(this.drawTimerCallback, null, 200, 200);
        }

        void FormClosingHandler(object sender, FormClosingEventArgs e)
        {
            this.button1.Enabled = false;
            this.dataTimer.Change(System.Threading.Timeout.Infinite, System.Threading.Timeout.Infinite);
            this.drawTimer.Change(System.Threading.Timeout.Infinite, System.Threading.Timeout.Infinite);
        }

        void StartTimer(object sender, EventArgs e)
        {
            this.dataTimer.Change(200, 200);
            this.button1.Text = "停止する";
            this.button1.Click -= this.StartTimer;
            this.button1.Click += this.StopTimer;
        }

        void StopTimer(object sender, EventArgs e)
        {
            this.dataTimer.Change(System.Threading.Timeout.Infinite, 200);
            this.button1.Text = "開始する";
            this.button1.Click -= this.StopTimer;
            this.button1.Click += this.StartTimer;
        }

        private void DataTimerCallback(object state)
        {
            ++this.additionalTime;
            var row = this.dataTable.NewRow();
            row["time"] = this.additionalTime;
            row["data"] = Math.Sin(this.additionalTime) + 1;
            bool taken = false;
            this.locker.Enter(ref taken);
            this.dataTable.Rows.Add(row);
            this.dataTable.Rows.RemoveAt(0);
            if (taken)
            {
                this.locker.Exit();
            }
        }

        private void drawTimerCallback(object state)
        {
            if (this.IsDisposed == false)
            {
                if (this.InvokeRequired)
                {
                    this.Invoke(this.drawAction);
                }
                else
                {
                    this.drawGraph();
                }
            }
        }

        private void drawGraph()
        {
            bool taken = false;
            this.locker.Enter(ref taken);
            this.chart1.DataBind();
            if (taken)
            {
                this.locker.Exit();
            }
        }
    }
}