how to update datagridview selected row values

private void btnedit_Click(object sender, EventArgs e)
        {
            
           

            DialogResult dr = MessageBox.Show("Are you sure to save Changes", "Message", MessageBoxButtons.YesNoCancel, MessageBoxIcon.Information);
            if (dr == DialogResult.Yes)
            {

               
                   con.Open();
                 
                    string strQuery = "update tblProducts set ProductsId='" + textBox1.Text+ "',CategoryName='" + comboBox1.Text + "',ProductsName='" + txtpname.Text + "',ProductsDescription='" + txtpdes.Text + "',ProductsPrice='" + txtpprice.Text + "' where ProductsId=" + textBox1.Text;
                    SqlCommand cmdSelect = new SqlCommand(strQuery, con);
                    cmdSelect.ExecuteNonQuery();
                    con.Close();
                  // bindgrid();

                
            }
           
           
        }