Basic DataGridView

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;

namespace BasicGridView
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            InitDataGridView();
        }

        private void InitDataGridView()
        {
            //initialize different fields of our object
            //see also in the designer.cs file
            dataGridView1.ColumnCount = 4;
            dataGridView1.Columns[0].Name = "Item";
            dataGridView1.Columns[1].Name = "Price";
            dataGridView1.Columns[2].Name = "Amount";
            dataGridView1.Columns[3].Name = "Total";
            // allow selectio of just one cell
            dataGridView1.MultiSelect = false;
            // show insertion point on entering a cell
            dataGridView1.EditMode = DataGridViewEditMode.EditOnEnter;
            // set other properties here          
        }

        private void button1_Click(object sender, EventArgs e)
        {
            // all this is by no means "waterproof" but just doing basic 
            // get some values from the grid, do a calculation and put the result back
            for (int row = 0; row < dataGridView1.Rows.Count; row++)
            {
                double unitprice = Convert.ToDouble(dataGridView1[1, row].Value);
                double amount = Convert.ToDouble(dataGridView1[2, row].Value);
                double total = unitprice * amount;
                dataGridView1.Rows[row].Cells[3].Value = total.ToString();
                dataGridView1[3, row].Value = total.ToString();
            }
        }
    }
}