how to exctrected email insert into csv file in C#?

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.IO;
using System.Text.RegularExpressions;
using Excel = Microsoft.Office.Interop.Excel;
using word = Microsoft.Office.Interop.Word;

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

        private void btnText_Click(object sender, EventArgs e)
        {
            string path = Application.StartupPath + @"\\E-mail-Text.txt";
            TextWriter tw = new StreamWriter(path);
            tw.Close();
            //else if (File.Exists(path))
            //    {
            //   TextWriter tw = new StreamWriter(path);
            //   tw.WriteLine("The next line!");
            //   tw.Close(); 
            //            }
            //StreamWriter tw11 = new StreamWriter("j.txt");
            //tw11.WriteLine("hiiiiiiiiii");
            //char ch;
            //int Tchar = 0;
            //int size = -1;
            DialogResult result = openFileDialog1.ShowDialog(); // Show the dialog.
            if (result == DialogResult.OK) // Test result.
            {
                string file = openFileDialog1.FileName;
                try
                {
                    string text = File.ReadAllText(file);
                    //size = text.Length;
                    // MessageBox.Show(file.ToString());
                    //label1.Text = text;
                    //StreamReader reader = new StreamReader(file);
                    //do
                    //{
                    //    ch = (char)reader.Read();
                    //    //label2.Text = ch.ToString();
                    //    if (Convert.ToInt32(ch) == 34)
                    //    {
                    //        Console.Write(@";");
                    //    }
                    //    Tchar++;
                    //} while (!reader.EndOfStream);

                    const string MatchEmailPattern =
      @"(([\w-]+\.)+[\w-]+|([a-zA-Z]{1}|[\w-]{2,}))@"
      + @"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\."
        + @"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|"
      + @"([a-zA-Z]+[\w-]+\.)+[a-zA-Z]{2,4})";
                    Regex rx = new Regex(MatchEmailPattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);
                    // Find matches.
                    MatchCollection matches = rx.Matches(text);
                    // Report the number of matches found.
                    int noOfMatches = matches.Count;
                    MessageBox.Show("E-mail Found ="+noOfMatches);
                    // Report on each match.
                    FileStream fs1 = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
                    StreamWriter writer = new StreamWriter(fs1);
                    foreach (Match match in matches)
                    {
                        string s = match.ToString();
                        writer.WriteLine(match.ToString() + ",");
                    }
                    writer.Close();

                    string sourceFilePath = path;
                    string destinationFilePath = path;
                    var readLines = File.ReadAllLines(sourceFilePath, Encoding.Default);
                    File.WriteAllLines(destinationFilePath, readLines.Distinct().ToArray(), Encoding.Default);
                }
                catch (Exception ex)
                {
                    MessageBox.Show("" + ex);
                }
            }
            MessageBox.Show("Successfully Extract E-mail"); // <-- Shows file size in debugging mode.
            //<-- For debugging use.
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //        StreamWriter writer =
            //             new StreamWriter("D:\\j.txt", true);

            //            writer.WriteLine("Important data line 1");

            //        // Append line to the file.
            //StreamWriter writer1 =
            //            new StreamWriter("D:\\j.txt", true);

            //            writer1.WriteLine("Line 2");



        }

        private void btnExcel_Click(object sender, EventArgs e)
        {
            string path = Application.StartupPath + @"\\E-mail-Excel.txt";
            TextWriter tw = new StreamWriter(path);
            tw.Close();
            DialogResult result = openFileDialog2.ShowDialog();
            Excel.Application xlApp;
            Excel.Workbook xlWorkBook;
            Excel.Worksheet xlWorkSheet;
            Excel.Range range;

            string str;
            int rCnt = 0;
            int cCnt = 0;

            if (result == DialogResult.OK) // Test result.
            {
                string file = openFileDialog2.FileName;
                xlApp = new Excel.Application();
                xlWorkBook = xlApp.Workbooks.Open(file, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
                xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
                range = xlWorkSheet.UsedRange;

                FileStream fs1 = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
                StreamWriter writer = new StreamWriter(fs1);

                for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++)
                {
                    for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++)
                    {
                        const string MatchEmailPattern =
         @"(([\w-]+\.)+[\w-]+|([a-zA-Z]{1}|[\w-]{2,}))@"
         + @"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\."
           + @"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|"
         + @"([a-zA-Z]+[\w-]+\.)+[a-zA-Z]{2,4})";
                        str = (string)(range.Cells[rCnt, cCnt] as Excel.Range).Value2;
                        if (str != null)
                        {
                            Regex rx = new Regex(MatchEmailPattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);
                            // Find matches.
                            MatchCollection matches = rx.Matches(str);
                            //int noOfMatches = matches.Count;
                            //MessageBox.Show("E-mail Found In " + cCnt +"Row" + noOfMatches);
                            foreach (Match match in matches)
                            {
                                //MessageBox.Show(match.ToString());
                                writer.WriteLine(match.ToString() + ",");
                            }
                        }
                    }

                }

                writer.Close();
                string sourceFilePath = path;
                string destinationFilePath = path;
                var readLines = File.ReadAllLines(sourceFilePath, Encoding.Default);
                File.WriteAllLines(destinationFilePath, readLines.Distinct().ToArray(), Encoding.Default);
                xlWorkBook.Close(true, null, null);
                xlApp.Quit();

                releaseObject(xlWorkSheet);
                releaseObject(xlWorkBook);
                releaseObject(xlApp);
                MessageBox.Show("Successfully Extract E-mail");
            }
        }

        private void releaseObject(object obj)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
                obj = null;
            }
            catch (Exception ex)
            {
                obj = null;
                MessageBox.Show("Unable to release the Object " + ex.ToString());
            }
            finally
            {
                GC.Collect();
            }
        }

        private void btnWord_Click(object sender, EventArgs e)
        {
            string path = Application.StartupPath + @"\\E-mail-Word.txt";
            TextWriter tw = new StreamWriter(path);
            tw.Close();
            DialogResult result = openFileDialog3.ShowDialog();
            if (result == DialogResult.OK) // Test result.
            {
                string file = openFileDialog3.FileName;
                try
                {
                    
                    // Open a doc file.
                    word.Document document;
                    word.Application application;
                    application = new word.Application();
                    document = application.Documents.Open(file);
                    
                    // Loop through all words in the document.
                    int count = document.Words.Count;
                    for (int i = 1; i <= count; i++)
                    {
                        // Write the word.
                        string str = document.Words[i].Text;
                    
                    }
                    document.ActiveWindow.Selection.WholeStory();

                    document.ActiveWindow.Selection.Copy();

                    IDataObject data = Clipboard.GetDataObject();

                    string text = data.GetData(DataFormats.Text).ToString();

                    const string MatchEmailPattern =
     @"(([\w-]+\.)+[\w-]+|([a-zA-Z]{1}|[\w-]{2,}))@"
     + @"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\."
       + @"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|"
     + @"([a-zA-Z]+[\w-]+\.)+[a-zA-Z]{2,4})";
                    Regex rx = new Regex(MatchEmailPattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);
                    // Find matches.
                    MatchCollection matches = rx.Matches(text);
                    // Report the number of matches found.
                    int noOfMatches = matches.Count;
                    MessageBox.Show("E-mail Found =" + noOfMatches);
                    // Report on each match.
                    FileStream fs1 = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
                    StreamWriter writer = new StreamWriter(fs1);
                    foreach (Match match in matches)
                    {
                        string s = match.ToString();
                        writer.WriteLine(match.ToString() + ",");
                    }
                    writer.Close();

                    string sourceFilePath = path;
                    string destinationFilePath = path;
                    var readLines = File.ReadAllLines(sourceFilePath, Encoding.Default);
                    File.WriteAllLines(destinationFilePath, readLines.Distinct().ToArray(), Encoding.Default);
                    document.Close();
                    application.Quit();
                  
                }
                catch (Exception ex)
                {
                    MessageBox.Show("" + ex);
                }
            }
            // Close word.
            MessageBox.Show("Successfully Extract E-mail");
           

        }
    }
}