openFileDialog Mainform.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Windows.Forms;

namespace TestOpenFileDialog
{
    /// <summary>
    /// Description of MainForm.
    /// </summary>
    public partial class MainForm : Form
    {
        public MainForm()
        {
            //
            // The InitializeComponent() call is required for Windows Forms designer support.
            //
            InitializeComponent();

            //
            // TODO: Add constructor code after the InitializeComponent() call.
            //
        }

        void Button1Click(object sender, EventArgs e)
        {
            DialogResult d = openFileDialog1.ShowDialog();
            if (d == DialogResult.OK)
            {
                string filename = openFileDialog1.FileName;
                FileStream f = new FileStream(filename, FileMode.Open);
                StreamReader sr = new StreamReader(f);
                //richTextBox1.Rtf = sr.ReadToEnd();
                sr.Close();
            }
        }
    }
}