Update values id don't save in database

Question

int editrowindex=-1;

//addbutton.Text="Add";

private void dataGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)

{

try

{

var senderGrid = (DataGridView)sender;

if (e.ColumnIndex == dataGridView.Columns["Delete"].Index && e.RowIndex >= 0)

{

dataGridView.Rows.RemoveAt(e.RowIndex);

int i = 1;

foreach (DataGridViewRow g1 in dataGridView.Rows)

{

g1.Cells[0].Value = i;

i++;

}

}

else if (e.ColumnIndex == dataGridView.Columns["Edit"].Index && e.RowIndex >= 0)

{

addbutton.Text = "Update";

editrowindex = e.RowIndex;

comboBoxproduct.Text = "";

comboBoxproduct.SelectedText= dataGridView.Rows[e.RowIndex].Cells[1].Value.ToString();

dectxt.Text = "";

dectxt.Text = dataGridView.Rows[e.RowIndex].Cells[2].Value.ToString();

txtqty.Text = "";

txtqty.Text= dataGridView.Rows[e.RowIndex].Cells[3].Value.ToString();

combounit.Text = "";

combounit.SelectedText = dataGridView.Rows[e.RowIndex].Cells[4].Value.ToString();

qtytxtprice.Text = "";

qtytxtprice.SelectedText = dataGridView.Rows[e.RowIndex].Cells[5].Value.ToString();

txttax.Text = "";

txttax.SelectedValue = dataGridView.Rows[e.RowIndex].Cells[6].Value.ToString();

Totaltxt.Text = "";

Totaltxt.SelectedText = dataGridView.Rows[e.RowIndex].Cells[7].Value.ToString();

}

}

catch { }

}