Use this code follow following setps.
1)Create class file and past this code
2)Past this code in button click event
textbox1.text =convert.tostring(funcation.id("select max(id) from demotable "));
using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;
using System.Windows.Forms;
namespace POS
{
class funcation //............>( class name)
{
//autoid
public static string id(string strSQL) //..........> (pass parameter to funcation id (id is funcation name))
{
string pi_id = null;
try
{
String userqry = "";
userqry = strSQL;
int i = 0;
SqlCommand cmd = new SqlCommand(userqry, datastore.Connection());
SqlDataReader dr = cmd.ExecuteReader();
if (dr.HasRows)
{
while (dr.Read())
{
pi_id = dr[0].ToString();
}
if (pi_id.Equals(""))
{
pi_id = "001";
}
else
{
i = Convert.ToInt32(pi_id);
i++;
pi_id = "" + i;
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
return pi_id.ToString().TrimEnd();..........> (return value)
}
}
}
