Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Ampel
{
    public partial class Form1 : Form
    {
        private bool trafficBroken = false;
        public Form1()
        {
            InitializeComponent();
        }
        public void UpdateAmpel()
        {
            if (trafficBroken == false)
            {
                if (richTextBox1.BackColor == Color.Red && richTextBox2.BackColor == Color.White)
                {
                    richTextBox2.BackColor = Color.Yellow;
                    timer1.Interval = 500;
                    return;
                }
                if (richTextBox1.BackColor == Color.Red && richTextBox2.BackColor == Color.Yellow)
                {
                    richTextBox1.BackColor = Color.White;
                    richTextBox2.BackColor = Color.White;
                    richTextBox3.BackColor = Color.Green;
                    timer1.Interval = 2000;
                    return;
                }
                if (richTextBox1.BackColor == Color.White && richTextBox2.BackColor == Color.Yellow)
                {
                    richTextBox1.BackColor = Color.Red;
                    richTextBox2.BackColor = Color.White;
                    timer1.Interval = 1000;
                    return;
                }
                if (richTextBox3.BackColor == Color.Green)
                {
                    richTextBox3.BackColor = Color.White;
                    richTextBox2.BackColor = Color.Yellow;
                    timer1.Interval = 750;
                    return;
                }
            }
            else
            {
                if (timer1.Interval != 250)
                {
                    timer1.Interval = 250;
                    timer1.Stop();
                    timer1.Start();
                }
                if (richTextBox2.BackColor == Color.Yellow)
                {
                    richTextBox2.BackColor = Color.White;
                }
                else if (richTextBox2.BackColor == Color.White)
                {
                    richTextBox2.BackColor = Color.Yellow;
                }
                if (richTextBox1.BackColor != Color.White)
                {
                    richTextBox1.BackColor = Color.White;
                }
                if (richTextBox3.BackColor != Color.White)
                {
                    richTextBox3.BackColor = Color.White;
                }
                return;
            }
            return;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (timer1.Enabled == true)
            {
                timer1.Stop();
                button1.Text = "Start!";
            }
            else
            {
                timer1.Start();
                button1.Text = "Stop!";
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            progressBar1.Value = 0;
            button1.Text = "Start";
            richTextBox1.BackColor = Color.Red;
            richTextBox2.BackColor = Color.White;
            richTextBox3.BackColor = Color.White;
            timer1.Stop();
            trafficBroken = false;
            richTextBox4.Text = "";
            timer1.Interval = 1000;
            button2.Enabled = false;
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            if (trafficBroken == false)
            {
                if (progressBar1.Value == 100)
                { progressBar1.Value = 0; }
                progressBar1.Value += 20;
                if (progressBar1.Value == 100)
                {
                    Random counte = new Random();
                    int count = counte.Next(0, 5);
                    if (count == 3)
                    {
                        richTextBox4.Text = "Die Ampel ist kaputt! Sie wird nun nur noch gelb leuchten! Klicke auf Reparieren, um die Ampel zu reparieren!";
                        trafficBroken = true;
                        button2.Enabled = true;
                        timer1.Interval = 250;
                        return;
                    }
                    UpdateAmpel();
                }
            }
            else UpdateAmpel();
        }
    }
}