OOPLAB10

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;
using System.Net;
using System.IO;


namespace OOP_LAB10
{
    public partial class Form1 : Form
    {
        private string folder;
        public Form1()
        {
            InitializeComponent();
            textBox1.Enter += textBox1_Enter;
            numericUpDown1.ValueChanged += NumericUpDown1_ValueChanged;
        }
        //Подходящий сайт http://smol-ray.ru/omsu/adm/teksty-oficialnyh-vystuplenij-1215/
        private void NumericUpDown1_ValueChanged(object? sender, EventArgs e)
        {
            int a = (int)numericUpDown1.Value;
            if (a < 0 || a > 49151)
                numericUpDown1.Value = 80;
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }
        private void textBox1_Enter(object sender, EventArgs e)
        {
            textBox1.Text = "http://";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            var save = new SaveFileDialog();
            save.Filter = "Text files(*.txt)|*.txt|All files(*.*)|*.*";
            if (save.ShowDialog() != DialogResult.OK) { return; }
            textBox2.Text = save.FileName;
            folder = save.FileName;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (folder == null)
            {
                MessageBox.Show("Select folder");
                return;
            }
            long ch;
            try
            {
                var req = (HttpWebRequest)WebRequest.Create(textBox1.Text + ":" + numericUpDown1.Value);
                var resp = (HttpWebResponse)req.GetResponse();
                var istrm = resp.GetResponseStream();
                var fs = new FileStream(folder, FileMode.Create);
                var streamWriter = new StreamWriter(fs);
                for (long i = 1; ; i++)
                {
                    ch = istrm.ReadByte();
                    if (ch == -1) break;
                    var data = Convert.ToString((char)ch);
                    streamWriter.Write(data);
                    progressBar1.Increment(1);
                }
                resp.Close();
                streamWriter.Close();
                fs.Close();
                MessageBox.Show("Success!");
                progressBar1.Value = 0;
            }
            catch (Exception b)
            {
                MessageBox.Show(b.Message);
            }
        }
    }
}