panel

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

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        List<user> u = new List<user>();
        user User = new user();

        public Form1()
        {
            InitializeComponent();

            u.Add(new user("admin", "abc123", true));
            u.Add(new user("mg", "xyz123", true));
            u.Add(new user("pwsip", "informatyka", false));
        }

        private void button_Zaloguj_Click(object sender, EventArgs e)
        {
            string maskPassword = User.encryptPassword(textBox_PASSWORD.Text);
            //zmienna w której przechowujemy wprowadzone hasło i przekazujemy haslo do porownywacza
            foreach (user us in u)
            {
                if (us.UserName == textBox_LOGIN.Text && us.checkPassword(maskPassword))
                {
                    Form2 okno = new Form2(this, us.UserName, us.isAdmin);
                    okno.Show();
                    this.Hide();
                }
                else if (us.UserName != textBox_LOGIN.Text && us.checkPassword(maskPassword))
                {
                    //MessageBox.Show("Sprawdź login lub hasło i spróbuj jeszcze raz.", "Błąd logowania");
                    textBox_LOGIN.Clear();
                    textBox_PASSWORD.Clear();
                }

            }
            if (textBox_LOGIN.Text != "admin" && textBox_LOGIN.Text != "mg" && textBox_LOGIN.Text != "pwsip")
            {
                MessageBox.Show("Sprawdź login lub hasło i spróbuj jeszcze raz.", "Błąd logowania");
                textBox_LOGIN.Clear();
                textBox_PASSWORD.Clear();
            }

        }

        private void button_Zamknij_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox_LOGIN_TextChanged(object sender, EventArgs e)
        {

        }

        private void textBox_PASSWORD_TextChanged(object sender, EventArgs e)
        {
            textBox_PASSWORD.PasswordChar = '*';
        }


    }
}