szyfrcezara:MainWindow.xaml.cs

using Microsoft.Win32;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace szyfrcezara
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        Queue arrayToCode = new Queue();

        char[] abecadlo = { 'A', 'B', 'C', 'D' ,'E' ,'F' ,'G' ,'H' ,'I' ,'J' ,'K' ,'L' ,'M' ,'N' ,'O' ,'P' ,'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
        int klucz = 3;

        private void wczytaj_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog dialog = new OpenFileDialog();
            if (dialog.ShowDialog() == true)
            {
                input.Text = File.ReadAllText(dialog.FileName);
            }
        }

        private void zapisz_Click(object sender, RoutedEventArgs e)
        {
            string fileText = input.Text;

            SaveFileDialog dialog = new SaveFileDialog()
            {
                Filter = "Text Files(*.txt)|*.txt|All(*.*)|*"
            };

            if (dialog.ShowDialog() == true)
            {
                File.WriteAllText(dialog.FileName, fileText);
            }
        }

        private void zakoduj_Click(object sender, RoutedEventArgs e)
        {
            output.Text = "";
            string codedString = "";
            foreach (char letter in input.Text.ToUpper())
            {
                if(letter != ' ')
                {
                    arrayToCode.Enqueue(letter);
                }
            }

            foreach (char letter in arrayToCode)
            {
                //output.Text += Array.IndexOf(abecadlo, letter);
                int x = Array.IndexOf(abecadlo, letter);
                if (letter != '_')
                {
                    if (x <= 25 - klucz)
                    {
                        codedString += abecadlo[x + klucz];
                    }
                    else
                    {
                        codedString += abecadlo[(x + 3) % 26];
                    }
                }

                else
                {
                    codedString += "_";
                }
            }
            output.Text = codedString;
            arrayToCode.Clear();
        }

        private void dekoduj_Click(object sender, RoutedEventArgs e)
        {
            output.Text = "";
            string decodedString = "";
            foreach (char letter in input.Text.ToUpper())
            {
                if (letter != ' ')
                {
                    arrayToCode.Enqueue(letter);
                }
            }

            foreach (char letter in arrayToCode)
            {
                //output.Text += Array.IndexOf(abecadlo, letter);
                int x = Array.IndexOf(abecadlo, letter);
                if (x != '_')
                {
                    if (x >= klucz)
                    {
                        decodedString += abecadlo[x - klucz];
                    }
                    else
                    {
                        decodedString += abecadlo[x+23];
                    }
                }

                else
                {
                    decodedString += "_";
                }
            }
            output.Text = decodedString;
            arrayToCode.Clear();
        }
    }
}