How to sort the content of file using merge sort..

write a program that sorts a content of txt file using an external merge sort????????
we r done with the coding of browse a file and shown in text file..
we dont knw how to apply the merge sort on txt file and then again sort it in array.
In Form we used brows button,append button,2 textview,merge button,write button and sort in array button,,,,,,,,,
plz anyone help us
here our coding

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 Splitfiles
{

    public partial class Form1 : Form
    {
        public FileStream fs;
        System.IO.StreamWriter writer;

        string file_write;

        public Form1()
        {
            InitializeComponent();
        }


        //List<string> Packets = new List<string>();

        //Merge file is stored in drive
        //string SaveFileFolder = @"c:\";

        private void brows_Click(object sender, EventArgs e)
        {
            try
            {
                openFileDialog1.ShowDialog();
                txtBrowsFile.Text = openFileDialog1.FileName;

                fs = new FileStream(txtBrowsFile.Text, FileMode.Open, FileAccess.Read);
                string name = Path.GetFileName(txtBrowsFile.Text);
                //int FileLength = (int)fs.Length / 1024;

            }
            catch (Exception ex)
            {
                lblSendingResult.Text = "EXCEPTION:" + ex;
            }
        }



        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            //string fpath="E:\\one.txt";
            string name = Path.GetFileName(txtBrowsFile.Text);
            StreamReader dr = new StreamReader(Path.GetFileName(txtBrowsFile.Text));



            while (dr.Peek() != -1)
            {
                string contents = dr.ReadToEnd();
                /*string[] mer = new string[contents.Length];
                int len = contents.Length;
                int i = 0;
                for (i = 0; i < len; i++)
                {
                    mer[i] = (contents);*/


                textBox1.Text = contents;


            }

            txtBrowsFile.Clear();

        }

        private void button2_Click(object sender, EventArgs e)
        {
            //StreamWriter dw = new StreamWriter(Path.GetFileName(txtBrowsFile.Text));


        }

        private void button3_Click(object sender, EventArgs e)
        {
            string name = Path.GetFileName(txtBrowsFile.Text);
            StreamReader dr = new StreamReader(Path.GetFileName(txtBrowsFile.Text));
            string content;

            content = dr.ReadToEnd().ToString();

            textBox2.Text = textBox1.Text + (content);
            textBox1.Clear();


        }

        private void button4_Click(object sender, EventArgs e)
        {


            //string name = Path.GetFileName(txtBrowsFile.Text);
            //StreamWriter dw = new StreamWriter (Path.GetFileName(txtBrowsFile.Text),true);
            //StreamWriterfile_write = "Path.GetFileName(txtBrowsFile.Text)";
            //writer = new System.IO.StreamWriter(file_write, true);
            //dw.Write(textBox2.Text);
            //dw.Close();
            file_write = "C:\\Users\\asadali\\Documents\\file.txt";
            writer = new System.IO.StreamWriter(file_write);
            writer.Write(textBox2.Text);
            
            writer.Close();
            MessageBox.Show("wrote File");
        }

        private void button5_Click(object sender, EventArgs e)
        {
            string name = "C:\\Users\\asadali\\Documents\\file.txt";
            StreamReader dr = new StreamReader(name);
            while (dr.Peek() != -1)
            {
                string contents = dr.ReadToEnd();
                string[] mer = new string[contents.Length];
                int len = contents.Length;
                int i = 0;
                for (i = 0; i < len; i++)
                {
                    mer[i] = (contents);
                    textBox1.Text = contents;

                }
                /*   string[] arr = textBox2.Lines;
                   int i;
                   for (i = 0; i < arr.Length; i++)
                   {

                       textBox2.Text = arr[i];

                       i++;
                       arr[i] = textBox1.Text;
                   }*/

            }
            //string [] contentss = textBox2.Lines.ToArray();

            // for( int i=0;i<contentss.length;i++)>
            //{

            //string[] lines = File.ReadAllLines("C:\\Users\\asidali\\Documents\\file.txt");

            //string[] a = new string[lines.Length];
            //int i;
            //for ( i = 0; i < lines.Length; i++)
            //{
            //  lines[i] = a[i];
            //a[i] = textBox1.Text;
            //}
            //.textBox1a[i] = textBox1.Text;
        }
    }
}
            /*string name = Path.GetFileName(txtBrowsFile.Text);
            StreamReader dr = new StreamReader(Path.GetFileName(txtBrowsFile.Text));

            while (dr.Peek() != -1)
            {
                string contents = dr.ReadToEnd();
                string[] mer = new string[contents.Length];
                int len = contents.Length;
                int i = 0;
                for (i = 0; i < len; i++)
                {
                    mer[i] = (contents);


                    textBox1.Text = contents;

                }

                //string[] lines = this.textBox1.Text.Split('\n');
                //MessageBox.Show(lines.Length.ToString());

        }
    }
            /*private string[] Mergeso                                                                                                                                            rt(string[] mer)
 {
     if (mer.Length <= 1)
     {
         return mer;
     }

     int firstPart = mer.Length / 2;
     string[] strings1 = new string[firstPart];
     string[] strings2 = new string[mer.Length - firstPart];

     string[] sorted = new string[mer.Length];

     // Split the array into two;
     for (int i = 0; i < firstPart; i++)
     {
                                                                                                                                                                                                                                                                                                                                                                                                                  strings1[i] = mer[i];
     }

     for (int i = firstPart; i < mer.Length; i++)
     {
         strings2[i - firstPart] = mer[i];
     }

     strings1 = Mergesort(strings1);
     strings2 = Mergesort(strings2);

     int j = 0;
     int k = 0;

     for (int i = 0; i < sorted.Length; i++)
     {
         if (j == strings1.Length)
         {
             sorted[i] = strings2[k];
             k++;
         }
         else if (k == strings2.Length)
         {
             sorted[i] = strings1[j];
             j++;
         }
         else if (stringcompare(strings1[j], strings2[k]))
         {
             sorted[i] = strings1[j];
             j++;
         }
         else
         {
             sorted[i] = strings2[k];
             k++;
         }
     }

     return sorted;
 }
        
}*/</string></string>

Tags: C#, Visual Studio, Forms