How to save object of a class to a file and reload it...........

U r problem can be solver using Serializeand Deserialize concept
see this 1st u should have namespaces

using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;

then create a class

[Serializable]
    class Class1
    {
        public string name;
        public string ID;
        public string address;
    }

Serializable is a key word we need to use it

then in main program write this code

BinaryFormatter bnf = new BinaryFormatter();
MemoryStream ms = new MemoryStream();

Class1 obj = new Class1();
obj.name = "Arun";
obj.ID = "007";
obj.address="Mysore";

bnf.Serialize(ms, obj);
byte[] obj_content = ms.ToArray();

//File.Create("C:\\arun.arv");
//File.WriteAllBytes("C:\\arun.arv", obj_content);
FileStream fs1 = new FileStream("C:\\arun.arv", FileMode.Create);
BinaryWriter write = new BinaryWriter(fs1);
write.Write(obj_content);
write.Close();
fs1.Close();

FileStream fs = new FileStream("C:\\arun.arv",FileMode.Open);
BinaryReader read=new BinaryReader (fs);
byte[] obj_converter = new byte[fs.Length];
read.Read(obj_converter, 0, obj_converter.Length);



MemoryStream ms1 = new MemoryStream(obj_converter);
BinaryFormatter bnf1 = new BinaryFormatter();
ms1.Position = 0;

Class1 obj2 = (Class1)bnf1.Deserialize(ms1);
Console.Write(obj2.name);
Console.Write(obj2.ID);
Console.Write(obj2.address);