Question

怎么在c#中编写一个可以使交通信号灯一闪一闪的代码

Answer 1

namespace 交通灯信号演示
{
    public partial class Form1 : Form
    {
        private Timer tInstance = new Timer();
        private Action action;    // 执行交通灯闪烁的代理委托
        private TrafficLightColor tlColor=TrafficLightColor.Red;

        /// <summary>
        /// 交通灯枚举
        /// </summary>
        enum TrafficLightColor
        {
            Red=1,
            Yellow=2,
            Green=4
        }

        public Form1()
        {
            InitializeComponent();

            tInstance.Interval = 500; // 0.5秒间隔
            tInstance.Tick += tInstance_Tick;
            tInstance.Enabled = true;
            action = new Action(Run);
        }

        /// <summary>
        /// Tick事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void tInstance_Tick(object sender, EventArgs e)
        {
            tInstance.Enabled = false;

            action.BeginInvoke(null, null);

            tInstance.Enabled = true;
        }

        /// <summary>
        /// 控制交通灯闪烁 红->黄->绿
        /// </summary>
        private void Run()
        {
            Color cBackbround=Color.Red;

            switch (tlColor)
            {
                case TrafficLightColor.Red:
                    cBackbround = Color.Red;
                    tlColor = TrafficLightColor.Green;
                    break;
                case TrafficLightColor.Yellow:
                    cBackbround = Color.Yellow;
                    tlColor = TrafficLightColor.Red;
                    break;
                case TrafficLightColor.Green:
                    cBackbround = Color.Green;
                    tlColor = TrafficLightColor.Yellow;
                    break;
                default:
                    cBackbround = Color.Yellow;
                    break;
            }

            // 获取当前窗体的设备句柄
            Graphics g = this.CreateGraphics();  
            // 构造矩形对象,横纵坐标分别为100,
            // 矩形的宽100高100构成一个正方形,
            // 正方形的两个对角的长正好是圆的直径
            Rectangle rectE = new Rectangle(100, 100, 100, 100);
            // 画圆，直径为100
            g.DrawEllipse(new Pen(new SolidBrush(Color.Black)) , rectE);
            // 填充圆的表面积颜色
            g.FillEllipse(new SolidBrush(cBackbround), rectE);

        }
    }
}

Answer 2

用timer设置时间间隔变化颜色？

追问

恩，比如间隔60秒由红色变为绿色