asd

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 Bojenje_Krugova
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        SolidBrush cetka = new SolidBrush(Color.Blue);
        private void radioButton1_CheckedChanged(object sender, EventArgs e)
        {
            pictureBox1.Refresh();
            if (radioButton1.Checked)
            {
                Graphics g = pictureBox1.CreateGraphics();
                Pen olovka = new Pen(Color.Red, 5);
                g.DrawEllipse(olovka, 200, 50, 200, 200);
            }

        }

        private void groupBox1_Enter(object sender, EventArgs e)
        {

        }

        private void radioButton2_CheckedChanged(object sender, EventArgs e)
        {
            pictureBox1.Refresh();
            if (radioButton2.Checked)
            {
                Graphics g = pictureBox1.CreateGraphics();
                Pen olovka = new Pen(Color.Green, 5);
                g.DrawEllipse(olovka, 200, 50, 200, 200);
            }
        }

        private void radioButton3_CheckedChanged(object sender, EventArgs e)
        {
            pictureBox1.Refresh();
            if (radioButton3.Checked)
            {
                Graphics g = pictureBox1.CreateGraphics();
                Pen olovka = new Pen(Color.Blue, 5);
                g.DrawEllipse(olovka, 200, 50, 200, 200);
            }
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            if ((checkBox1.Checked) && (radioButton1.Checked))
            {
                Graphics g = pictureBox1.CreateGraphics();
                Brush cetka = new SolidBrush(Color.Red);
                g.FillEllipse(cetka, 200,50,200,200);
            }
            else if ((checkBox1.Checked) && (radioButton2.Checked))
            {
                Graphics g = pictureBox1.CreateGraphics();
                Brush cetka = new SolidBrush(Color.Green);
                g.FillEllipse(cetka, 200, 50, 200, 200);
            }
            else if ((checkBox1.Checked) && (radioButton3.Checked))
            {
                Graphics g = pictureBox1.CreateGraphics();
                Brush cetka = new SolidBrush(Color.Blue);
                g.FillEllipse(cetka, 200, 50, 200, 200);
            }
        }
    }
}