C#のWinFormsで直線を点滅させる。

タイマーで一定時間ごと白い線と黒い線を交互に表示しています。

namespace BlinkLine;

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        var sz = new Size(640, 480);

        var picbox = new PictureBox
        {
            Size = sz,
        };


        bool blinkFlag = false;
        var blackPen = new Pen(Brushes.Black, 3);
        var whitePen = new Pen(Brushes.White, 3);
        var startPos = new Point(80, 100);
        var endPos = new Point(260, 100);

        var timer = new System.Windows.Forms.Timer(this.components)
        {
            Interval = 250,
        };
        timer.Tick += (s, e) =>
        {
            blinkFlag = !blinkFlag;
            picbox.Invalidate();
        };
        Load +=(s, e) =>
        {
            timer.Start();
        };
        picbox.Paint +=(s, e) =>
        {
            e.Graphics.Clear(Color.LightGray);
            var pen = blinkFlag ? blackPen : whitePen;
            e.Graphics.DrawLine(pen, startPos, endPos);
        };
        Closed +=(s, e) =>
        {
            timer.Stop();
            using(timer){}
        };

        Controls.Add(picbox);
    }
}