remove row from temporary gridview

private void btnDeleteTask_Click(object sender, EventArgs e)
        {
            DataTable newDataTable = new DataTable();
            if (dataGridView1.SelectedRows.Count > 0)
            {
                foreach (DataGridViewRow r in dataGridView1.SelectedRows)
                {
                    dataGridView1.Rows.Remove(r);
                }
                newDataTable = ((DataTable)dataGridView1.DataSource).Copy();
                dbContext.UpdateDataAdapter(newDataTable);
            }
            else
            {
                //
            }