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);
        }
        Panel panel1;
        TreeView treeView1;
        Button button1;
        void Form1_Load(object sender, EventArgs e)
        {
            treeView1 = new TreeView();
            treeView1.Name = "treeView1";
            treeView1.Dock = DockStyle.Fill;
            this.Controls.Add(treeView1);

            panel1 = new Panel();
            panel1.Name = "panel1";
            panel1.Dock = DockStyle.Bottom;
            panel1.Height = 26;
            this.Controls.Add(panel1);

            button1 = new Button();
            button1.Name = "button1";
            button1.Text = "button1";
            panel1.Controls.Add(button1);
            this.Set();
            this.SizeChanged += new EventHandler(Form1_SizeChanged);
        }

        void Set()
        {
            int bw = button1.Width / 2;
            int bh = button1.Height /2;
            int pw = panel1.ClientSize.Width / 2;
            int ph = panel1.ClientSize.Height /2;
            button1.Location = new Point(pw - bw, ph - bh);
        }

        void Form1_SizeChanged(object sender, EventArgs e)
        {
            this.Set();
        }
    }
}