Fix: Object reference not set to instance of object

Question

 The exception is thrown at line if (bool.Parse(row.Cells[0].Value.ToString())).

 Exception details:

System.NullReferenceException: 'Object reference not set to an instance of an object.'

System.Windows.Forms.DataGridViewCell.Value.get returned null.

private void btnDeleteCategory_Click(object sender, EventArgs e)

{

foreach (DataGridViewRow row in CategoryGV.Rows)

{

if (bool.Parse(row.Cells[0].Value.ToString()))

{

string cs = ConfigurationManager.ConnectionStrings["aladin"].ConnectionString;

SqlConnection con = new SqlConnection(cs);

SqlCommand cmd = new SqlCommand("DELETE FROM lwpos_categories WHERE id= '" + Convert.ToInt32(row.Cells[1].Value) + "' ", con);

con.Open();

cmd.ExecuteNonQuery();

con.Close();

}

}

MessageBox.Show("Deleted Successfully", "Successfull operation", MessageBoxButtons.OK, MessageBoxIcon.Information);

}