//삭제버튼
        private void simpleButton5_Click(object sender, EventArgs e)
        {
            if (dataGridView1.RowCount < 1)
            {
                MessageBox.Show("삭제할 항목이 없습니다.", "에러", MessageBoxButtons.OK);
                return;
            }

            int ID = (int)dataGridView1.SelectedCells[0].Value;

            using (DeskAssemblyEntities db = new DeskAssemblyEntities())
            {
                try
                {
                    Item item = db.Items.Find(ID);
                    db.Items.Remove(item);
                    db.SaveChanges();
                    MessageBox.Show("삭제 완료", "삭제", MessageBoxButtons.OK);

                    itemBindingSource.RemoveCurrent();
                }
                catch (Exception ex)
                {
                    MessageBox.Show("삭제할 항목이 없습니다.");
                }
            }
        }
        //등록버튼
        private void simpleButton3_Click(object sender, EventArgs e)
        {
            using (DeskAssemblyEntities db = new DeskAssemblyEntities())
            {
                if (textBox1.Text == "" && textBox2.Text == "")
                {
                    return;
                }

                Item item = new Item();
                item.Name  = textBox1.Text;
                item.Price = int.Parse(textBox2.Text);

                if (comboBoxEdit1.Text == "부품")
                {
                    item.IsProduct = false;
                }
                else if (comboBoxEdit1.Text == "제품")
                {
                    item.IsProduct = true;
                }
                else
                {
                    return;
                }

                item.Image = ConvertImageToByte(pictureBox1.Image);
                db.Items.Add(item);
                db.SaveChanges();

                if (item.IsProduct == false)
                {
                    MessageBox.Show("부품 등록 완료", "Message", MessageBoxButtons.OKCancel);
                }
                else
                {
                    MessageBox.Show("제품 등록 완료", "Message", MessageBoxButtons.OKCancel);
                }
                itemBindingSource.Add(item);
            }

            textBox1.Text     = "";
            textBox2.Text     = "";
            textBox4.Text     = "";
            pictureBox1.Image = null;
        }
        //수정버튼
        private void simpleButton4_Click(object sender, EventArgs e)
        {
            int ID = (int)dataGridView1.SelectedCells[0].Value;

            using (DeskAssemblyEntities db = new DeskAssemblyEntities())
            {
                if (textBox1.Text == "" && textBox2.Text == "")
                {
                    return;
                }

                Item item = db.Items.Find(ID);
                if (item != null)
                {
                    item.Name  = textBox1.Text;
                    item.Price = int.Parse(textBox2.Text);

                    if (comboBoxEdit1.Text == "부품")
                    {
                        item.IsProduct = false;
                    }
                    else if (comboBoxEdit1.Text == "제품")
                    {
                        item.IsProduct = true;
                    }
                    else
                    {
                        return;
                    }

                    item.Image = ConvertImageToByte(pictureBox1.Image);
                    db.SaveChanges();
                    itemBindingSource.DataSource = db.Items.ToList();
                }
            }
        }