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 WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            this.Load += new EventHandler(Form1_Load);
        }
        PictureBox pictureBox1 = new PictureBox();
        void Form1_Load(object sender, EventArgs e)
        {
            pictureBox1.Dock = DockStyle.Fill;
            pictureBox1.BackColor = Color.Magenta;
            this.Controls.Add(pictureBox1);
            string s = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
            Bitmap bmp1 = new Bitmap(s + "\\aaa.png");
            Bitmap bmp2 = new Bitmap(s + "\\bbb.png");
            using (Graphics g = Graphics.FromImage(bmp1))
            {
                g.DrawImage(bmp2, 0, 0);
            }
            pictureBox1.Image = bmp1;
            this.ClientSize = bmp1.Size;
        }
    }
}