Form3.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ProductTrackingSystem
{
    public partial class Form3 : Form
    {
        public Form3()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            dataGridView1.Rows.Add(textBox7.Text, textBox2.Text, textBox3.Text, textBox8.Text, textBox4.Text, textBox6.Text);
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            textBox5.Text = "";
            textBox6.Text = "";
            textBox7.Text = "";
            textBox8.Text = "";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
            excel.Visible = true;
            Microsoft.Office.Interop.Excel.Workbook workbook = excel.Workbooks.Add(System.Reflection.Missing.Value);
            Microsoft.Office.Interop.Excel.Worksheet sheet1 = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Sheets[1];

            int startCol = 1;
            int startRow = 1;
            for (int i = 0; i < dataGridView1.Columns.Count; i++)
            {
                Microsoft.Office.Interop.Excel.Range myRange = (Microsoft.Office.Interop.Excel.Range)sheet1.Cells[startRow, startCol + i];
                myRange.Value2 = dataGridView1.Columns[i].HeaderText;
            }
            startRow++;

            for (int i = 0; i < dataGridView1.Rows.Count; i++)
            {
                for (int j = 0; j < dataGridView1.Columns.Count; j++)
                {
                    Microsoft.Office.Interop.Excel.Range myRange = (Microsoft.Office.Interop.Excel.Range)sheet1.Cells[startRow + i, startCol + j];
                    myRange.Value2 = dataGridView1[j, i].Value == null ? "" : dataGridView1[j, i].Value;
                }
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (dataGridView1.SelectedRows.Count != 0)
            {
                foreach (DataGridViewRow row in dataGridView1.SelectedRows)
                    dataGridView1.Rows.Remove(row);
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            Form1 form1 = new Form1();
            form1.Show();
            this.Close();
        }

        private void button5_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}