How to read and write file using Stream Reader and Stream Writer?

[Arjun Sarankulu]

 
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
 
namespace PNB
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
 
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                if (openFileDialog1.FileName == "")
                {
                    MessageBox.Show("File Not Selected", "Error");
 
                } //if (openFileDialog1.FileName == "")
 
                StreamWriter SW;
                StreamReader SR;
                //string S;
                //string SingleLine = "";
                string bn = "";
                //if (rbPNB.Checked == true) { bn = "PNB"; } else { bn = "Ace"; }
 
                SR = File.OpenText(openFileDialog1.FileName);
                //SW = File.CreateText("D:\\PNB\\" + bn + "1.txt");
                SW = File.CreateText("D:\\PNB\\1.txt");
 
                int[] numbers = {15, 18, 26, 27, 44, 74, 79, 99, 104, 114, 120, 128, 129, 146, 149, 154,
                    169, 179, 184, 190 ,196, 198, 199, 211, 221, 241, 246, 276, 316, 356, 396,
                    436, 476, 493, 510, 527, 544, 561, 591, 607, 619, 629, 639, 648, 652, 908
                        }; //int[] numbers 
                //string strpos = System.Configuration.ConfigurationManager.AppSettings["array"];
                //char[] sep = { ',' };
                //string[] arraynum = strpos.Split(sep);
 
                //string strpos1 = System.Configuration.ConfigurationManager.AppSettings["array1"];
                //char[] sep1 = { ',' };
                //string[] arraynum1 = strpos1.Split(sep1);
 
                //int[] number = { 10, 1, 4, 5, 5, 29, 30, 8, 6, 39 };//int[] number
 
                string[] arr = { };//string[] arr
                int n = numbers.Length;
                int b = 0;
                int c = 0;
                int s;
                int numberslength = numbers.Length;
                //int numlength = arraynum.Length;
                string SingleLine = "";
                string S;
                while ((SingleLine = SR.ReadLine()) != null)
                //while (!SR.EndOfStream)               
                {
                    //if (bn == "Ace")
                    //{
 
                    S = SR.ReadLine();
 
                    for (int i = 0; i < n; i++)
                    {
                        if (i == 0)
                        {
                            s = -1;
                            int a = numbers[i];
                            b = s + 1;
                            c = a - b + 1;
 
                            //Console.WriteLine("Start:\t" + b);
                            //Console.WriteLine("End:\n" + c);
                        }
                        else
                        {
                            //int k = numbers[i - 1];
                            int a = numbers[i];
                            b = numbers[i - 1] + 1;//start
                            c = a - b + 1;//End
                            //Console.WriteLine("Start:\t" + p);
                            //Console.WriteLine("End:\n" + q);
                        }
 
                        SingleLine = String.Concat(SingleLine, S.Substring(b, c));
                        SingleLine = String.Concat(SingleLine, ",");
 
 
                        //string SingleLine = String.Concat(SingleLine, S.Substring(b, c));
                        //SingleLine = String.Concat(SingleLine, ",");
 
                    }//for (int i = 0; i < n; i++)
 
                    string st = SingleLine;
 
                    arr = st.Split(',');
 
                    int index;
                    string outputstring = "";
                    if (rbPNB.Checked == true)
                    {
                        bn = "PNB";
                        string strpos = System.Configuration.ConfigurationManager.AppSettings["array"];
                        char[] sep = { ',' };
                        string[] arraynum = strpos.Split(sep);
 
                        for (int j = 0; j < arraynum.Length; j++)
                        {
                            index = Int32.Parse(arraynum[j]) - 1;
                            outputstring += arr[index] + ",";
                        }
                    }//if (bn == "Ace")
 
                    else
                    {
                        bn = "Ace";
                        string strpos1 = System.Configuration.ConfigurationManager.AppSettings["array1"];
                        char[] sep1 = { ',' };
                        string[] arraynum1 = strpos1.Split(sep1);
                        for (int j = 0; j < arraynum1.Length; j++)
                        {
                            index = Int32.Parse(arraynum1[j]) - 1;
                            outputstring += arr[index] + ",";
                        }
                    }
                    SingleLine = outputstring.Trim(',');
                    SW.WriteLine(SingleLine);
 
                    // }//if (bn == "Ace")                              
 
 
 
 
                } // while ( !SR.EndOfStream ) 
 
                SR.Close();
                SW.Close();
 
                MessageBox.Show("Sucessful File Conversion to " + bn);
            }//try
            catch(Exception er) {
                MessageBox.Show("Error : "+ er.Message);
            }
        } // Private Button1 click
 
 
 
 
        private void button2_Click(object sender, EventArgs e)
        {
            while (openFileDialog1.FileName == "")
            {
                openFileDialog1.ShowDialog();
            }//End of While Loop
 
 
        }//End Of button2_click
 
        private void rbPNB_CheckedChanged(object sender, EventArgs e)
        {
 
        }//End of rbPNB_checkedChanged
 
        private void rbAce_CheckedChanged(object sender, EventArgs e)
        {
 
        }//End of rbAce_checkedChanged
 
    }//End Of the class Form1
 
}//End of Namespace PNB
 
 

The above code accept file from file Dialog
when i take txt file it convert the file to the respective format and if i take other than this format it creates the empty file and goes to the catch exception and display the following error in the Message Box -->"Error:Index and length must refer to a location within the string" Parameter name : Length