اشکال در ویرایش فایل notpad در سی شارپ

[milititi]

سلام--اطلاعات مشتری رو تو نوت پد ذخیره کردم--ذخیره و سرچ جواب میده--ولی ویرایش و حذف جواب نمیده-----ایراد کجاست؟؟؟؟!!!



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 WindowsFormsApplication1
{
public partial class customerinfo1 : Form
{
public class customers
{
public int idcustom,phone;
public string family,company,address;
}
public customerinfo1()
{
InitializeComponent();
}
private void customer_Load(object sender, EventArgs e)
{
textBox4.Text = "";
}

//save customer ذخيره اطلاعات مشتري
private void button1_Click(object sender, EventArgs e)
{
customers cust = new customers();
cust.idcustom = Int32.Parse(textBox1.Text);
cust.family = textBox2.Text;
cust.company = textBox3.Text;
cust.phone = Int32.Parse(textBox4.Text);
cust.address = textBox5.Text;
if (!File.Exists("c: \\ porozhe.txt"))
{
using (StreamWriter custt = File.CreateText("c:\\porozhe.txt"))
{
custt.WriteLine(textBox1.Text);
custt.WriteLine(textBox2.Text);
custt.WriteLine(textBox3.Text);
custt.WriteLine(textBox4.Text);
custt.WriteLine(textBox5.Text);
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = ""; } }
else
{
using (StreamWriter custt = File.AppendText("c:\\porozhe.txt"))
{
custt.WriteLine(textBox1.Text);
custt.WriteLine(textBox2.Text);
custt.WriteLine(textBox3.Text);
custt.WriteLine(textBox4.Text);
custt.WriteLine(textBox5.Text);
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = "";
textBox1.Focus();
}
}
}

//search
private void button2_Click(object sender, EventArgs e)
{
string s = " ";
using (StreamReader cust4 = File.OpenText("c:\\porozhe.txt"))
{
while ((s = cust4.ReadLine()) != null)
{
if (s == textBox6.Text.Trim())
{
customers cust2 = new customers();
cust2.family = cust4.ReadLine();
cust2.company = cust4.ReadLine();
cust2.phone = Convert.ToInt32(cust4.ReadLine());
cust2.address = cust4.ReadLine();
textBox1.Text = textBox6.Text;
textBox2.Text =cust2.family;
textBox3.Text = cust2.company;
textBox4.Text = Convert.ToString(cust2.phone);
textBox5.Text = cust2.address;
return;
}
} } }
// حذف
private void button3_Click(object sender, EventArgs e)
{
using (StreamWriter custt = File.AppendText("c:\\porozhe.txt"))
{
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = "";
custt.WriteLine(textBox1.Text);
custt.WriteLine(textBox2.Text);
custt.WriteLine(textBox3.Text);
custt.WriteLine(textBox4.Text);
custt.WriteLine(textBox5.Text);
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = "";
textBox1.Focus();
} } private void button5_Click(object sender, EventArgs e)
{
printPreviewDialog1.Document = printDocument1;
printPreviewDialog1.ShowDialog();
} private void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
using(StreamReader sw5=File.OpenText("c:\\porozhe.txt"))
string s = "" ;
int x=10 , y=10;
Font f1=new Font("arial black",10,FontStyle.Bold);



while (( s = sw5.ReadLine()) != null)
{

y+=20;
e.Graphics.DrawString(s,f1,Brushes.Black,10,y);
}
} /* // ویرایش
private void button4_Click(object sender, EventArgs e)
{
using (StreamWriter cust3 = File.AppendText("c:\\porozhe.txt"))
{
cust3.idcustom =Convert.ToInt32 (textBox1.Text);
cust3.family =(textBox2.Text);
custt.WriteLine(textBox3.Text);
custt.WriteLine(textBox4.Text);
custt.WriteLine(textBox5.Text);
cust3.De

}
} */
}
}