C#

command.Parameters.Add("@attach", SqlDbType.VarBinary).Value = bytFile;

Parameters.AddWithValue

command.Parameters.AddWithValue("@attach", bytFile);

private void btnGenerate_Click(object sender, EventArgs e)
       {
           //TODO: CLEAR PREVIOUS DRAWN
           panel3.Controls.Clear();

           //set rows and columns
           int rows = Convert.ToInt32(txtRows.Text);
           int columns = Convert.ToInt32(txtColumns.Text);

           PictureBox[,] map = new PictureBox[rows,columns];

           for (int j = 0; j < columns; j++)
           {
               for (int i = 0; i < rows; i++)
               {
                   //show dynamically
                   System.Threading.Thread.Sleep(50);

                   map[i, j] = new PictureBox();

                   map[i, j].Width = 45;
                   map[i, j].Height = 45;
                   map[i, j].BackColor = Color.NavajoWhite;

                   //set first picturebox position
                   if (i == 0 && j == 0)
                   {
                       map[i, j].Location = new Point(100, 100);
                   }


                   map[i, j].Location = new Point(45 * i + 100, 45 * j + 100);
                   map[i, j].BorderStyle = BorderStyle.Fixed3D;

                   //show on the panel
                   panel3.Controls.Add(map[i, j]);



               }
           }

       }

Child3 child3 = new Child3();
Child1 child1 = new Child1();
child3.Child1Button2Clicked += child1.child3_Child1Button2Clicked;
child3.Show();

public void child3_Child1Button2Clicked(object sender, FormsCommunication e)
{
    NumericalUD1.Visible = e.NumericalUDPass;
    textBox1.Text = e.textBoxPass;
    MessageBox.Show("it got fire" + ": " + e.NumericalUDPass.ToString() + ": " + e.textBoxPass.ToString());
 }

public event EventHandler<FormsCommunication> Child1Button2Clicked;

private void Child3Btn1_Click(object sender, EventArgs e)
{
    FormsCommunication formsCommunication = new 
    FormsCommunication("2782",Convert.ToBoolean(false));

    OnChild1Button2Clicked(formsCommunication);

}

protected virtual void OnChild1Button2Clicked(FormsCommunication e)
{
    Child1Button2Clicked?.Invoke(this, e);
}

public FormsCommunication(string textBox, bool NumericalUD)
 {
    textBoxPass = textBox;
    NumericalUDPass = NumericalUD;   
 }

 public string textBoxPass { get; private set; }
 public bool NumericalUDPass { get; private set; }