EonaCatDeDupText/EonaCatDeDupText/Form1.cs

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;
using System.IO;

namespace EonaCatDeDupText
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }


        private void ProceedBtn_Click(object sender, EventArgs e)
        {
            if (!File.Exists(InputRTB.Text))
            {
                MessageBox.Show("Error, please insert a correct file path to remove duplicate lines.");
                return;
            }
            else if (String.IsNullOrEmpty(OutputRTB.Text))
            {
                MessageBox.Show("Error, please insert a file path to save new file without duplicate lines.");
                return;
            }

            try
            {

                string content = File.ReadAllText(InputRTB.Text);

                List<string> repeatedList = content.Split(new string[] { Environment.NewLine }, StringSplitOptions.None).ToList();

                List<string> UnrepeatedList = repeatedList.Distinct().ToList();

                File.WriteAllLines(OutputRTB.Text, UnrepeatedList.ToArray());


            }
            catch (Exception exp)
            {
                MessageBox.Show("Error. " + exp.Message);
            }

            MessageBox.Show("File successfully created.");
        }



        private void InputBrowse_Click(object sender, EventArgs e)
        {
            openFileDialog1.FileName = "";
            DialogResult result = openFileDialog1.ShowDialog();
            if (result == DialogResult.OK)
            {
                InputRTB.Text = openFileDialog1.FileName;

                string ext = Path.GetExtension(InputRTB.Text);
                OutputRTB.Text = openFileDialog1.FileName.Replace(ext, "_DeDuped" + ext);
            }
        }

        private void OutputBrowse_Click(object sender, EventArgs e)
        {
            saveFileDialog1.Filter = "All Files (*.*)|*.*";
            DialogResult result = saveFileDialog1.ShowDialog();
            saveFileDialog1.InitialDirectory = InputRTB.Text;

            if (result == DialogResult.OK)
            {
                OutputRTB.Text = saveFileDialog1.FileName;
            }
        }
    }
}