C#_WinForms_MDI

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

namespace MDI_zad2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            MessageBox.Show("I have to save");
        }

        private void newToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Form2 childForm = new Form2();
            childForm.MdiParent = this;

            // random background color
            Random randonGen = new Random();
            Color randomColor = Color.FromArgb(randonGen.Next(255), randonGen.Next(255),randonGen.Next(255));
            childForm.BackColor = randomColor;

            // add a button
            Button btnAdd = new Button();
            btnAdd.Location = new Point(randonGen.Next(255), randonGen.Next(255));
            childForm.Controls.Add(btnAdd);

            // label with random background color
            Label lblAdd = new Label();
            lblAdd.BackColor = Color.FromArgb(randonGen.Next(255), randonGen.Next(255), randonGen.Next(255));
            lblAdd.Text = "I am a label";
            childForm.Controls.Add(lblAdd);

            childForm.Show();
        }

        private void graphicsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Form3 childForm = new Form3();
            childForm.MdiParent = this;
            childForm.Show();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {
            MessageBox.Show("I have to open");
        }
    }
}