Need help optimizing my code.

Question

Hi,

I am designing an application for a new project during the pandemic, it would be great if you could assist me in resolving the problems I am facing.

 

I am getting the following error. 

 

 

Also, Below is the code I'm using, it would be great if you could help me optimize the code,

I am looking to add data onto a datagridview table with SQL in the backend to be used as an Inventory Management System. It would be great if you could assist me in accomplishing the same. 

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;
using System.IO;
using System.Data.SqlClient;
using System.Configuration;
namespace Amal_Inventory
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
SqlConnection con = new SqlConnection(@"Data Source=D.\SQLEXPRESS;Initial Catalog=ReportServer$SQLEXPRESS;Integrated Security=True");
DataTable table = new DataTable();
int indexRow;
private void label1_Click(object sender, EventArgs e)
{
}
private void button3_Click(object sender, EventArgs e)
{
}
private void button4_Click(object sender, EventArgs e)
{
/*Microsoft.Office.Interop.Excel._Application = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel._Workbook workbook = Application.workbooks.Add(Type.Missing);
*/
}
private void button6_Click(object sender, EventArgs e)
{
}
private void button5_Click(object sender, EventArgs e)
{
if (MessageBox.Show("Sure ??", "Delete", MessageBoxButtons.OKCancel, MessageBoxIcon.Exclamation)==DialogResult.OK)
{
if (this.dataGridView1.SelectedRows.Count > 0)
{
dataGridView1.Rows.RemoveAt(this.dataGridView1.SelectedRows[0].Index);
}
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = "";
textBox6.Text = "";
textBox7.Text = "";
textBox8.Text = "";
textBox9.Text = "";
pictureBox1.Image = null;
}
}
private void button7_Click(object sender, EventArgs e)
{
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox4.Text = "";
textBox5.Text = "";
textBox6.Text = "";
textBox7.Text = "";
textBox8.Text = "";
textBox9.Text = "";
pictureBox1.Image = null;
}
private void button8_Click(object sender, EventArgs e)
{
Update();
}
private void button2_Click(object sender, EventArgs e)
{
MemoryStream mmst = new MemoryStream();
pictureBox1.Image.Save(mmst, pictureBox1.Image.RawFormat);
byte[] img = mmst.ToArray();
dataGridView1.Rows.Add(textBox1.Text, textBox2.Text, textBox3.Text, textBox4.Text, textBox5.Text,
textBox6.Text, textBox7.Text, textBox8.Text, img);
}
private void Form1_Load(object sender, EventArgs e)
{
string mainconn = ConfigurationManager.ConnectionStrings["MyCONN"].ConnectionString;
SqlConnection sqlconn = new SqlConnection(mainconn);
string sqlquery= "select * from [dbo].[tbl.Amal]";
sqlconn.Open();
SqlCommand sqlcomm = new SqlCommand(sqlquery, sqlconn);
SqlDataAdapter sdr = new SqlDataAdapter(sqlcomm);
DataTable dt = new DataTable();
sdr.Fill(dt);
dataGridView1.DataSource = dt;
sqlconn.Close();
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
DialogResult confirm = MessageBox.Show("Are you sure?", "Exit", MessageBoxButtons.YesNo);
}
private void button1_Click(object sender, EventArgs e)
{
OpenFileDialog openfiledialogue1 = new OpenFileDialog();
openfiledialogue1.Filter = "Choose Image (*.jpg;*.png;*.gif;*.jpeg)|*.jpg;*.png;*.gif;*.jpeg";
if (openfiledialogue1.ShowDialog() == DialogResult.OK)
{
pictureBox1.Image = new Bitmap(openfiledialogue1.FileName);
}
}
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
}
private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
}
private void button2_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
if (e.Control == true && e.KeyCode == Keys.L)
{
button2.PerformClick();
}
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
private void pictureBox1_LoadCompleted(object sender, AsyncCompletedEventArgs e)
{
}
private void pictureBox1_Click(object sender, EventArgs e)
{
}
private void Form1_TextChanged(object sender, EventArgs e)
{
}
private void pictureBox1_BackgroundImageChanged(object sender, EventArgs e)
{
}
private void pictureBox1_BackgroundImageChanged_1(object sender, EventArgs e)
{
}
private void groupBox2_Enter(object sender, EventArgs e)
{
}
private void textBox11_TextChanged(object sender, EventArgs e)
{
string mainconn = ConfigurationManager.ConnectionStrings["MyCONN"].ConnectionString;
SqlConnection sqlconn = new SqlConnection(mainconn);
string sqlquery= "select * from [dbo].[tbl.Amal] where Size='"+textBox1.Text+"'";
sqlconn.Open();
SqlCommand sqlcomm = new SqlCommand(sqlquery, sqlconn);
SqlDataAdapter sdr = new SqlDataAdapter(sqlcomm);
DataTable dt = new DataTable();
sdr.Fill(dt);
dataGridView1.DataSource = dt;
sqlconn.Close();
}
}
}