datagridview row font bold + mysql，.NET 3.5

Question

我的“信使”应用程序需要帮助。所有消息都显示在DGV中。我需要有“新消息”FontStyle.Bold。我比较日志和DGV，如果spravaDGV！= spravaLOGY然后DGV FontStyle.bold，但它不起作用

private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
   {

       if (e.RowIndex >= 0)
       {
           DataGridViewRow row = this.dataGridView1.Rows[e.RowIndex];

           citat.Text = "Správa od:  " + row.Cells["pc"].Value.ToString() + Environment.NewLine + "Dátum a čas:  " + row.Cells["datum"].Value.ToString()
               + Environment.NewLine + Environment.NewLine + "Správa:" + Environment.NewLine + row.Cells["sprava"].Value.ToString();
           spravaDGV = row.Cells["sprava"].Value.ToString();
           nacitanie_logu();
           zapisanie_logu();
           if (spravaDGV != spravaLOGY)
           {
               DataGridViewCellStyle style = new DataGridViewCellStyle();
               style.Font = new Font(dataGridView1.Font, FontStyle.Bold);
               dataGridView1.Rows[0].DefaultCellStyle = style;
           }
       }

   }

投入日志：

private void zapisanie_logu()
   {
       string constring = "Server=***;Database=OitDB;Uid=martin;Pwd=;";
       string Query = "INSERT INTO OitDB.logy(pc,sprava)VALUES(@pc,@sprava)";
       MySqlConnection conDatabase = new MySqlConnection(constring);
       MySqlCommand cmdDatabase = new MySqlCommand(Query, conDatabase);
       cmdDatabase.Parameters.AddWithValue("@sprava", spravaDGV);
       cmdDatabase.Parameters.AddWithValue("@pc", nazovPC);
       MySqlDataReader myReader;

       try
       {
           conDatabase.Open();
           myReader = cmdDatabase.ExecuteReader();
           MessageBox.Show("Správa odoslaná!");
           while (myReader.Read())
           {

           }

       }
       catch (Exception ex)
       {
           MessageBox.Show(ex.Message);

       }
   }

从日志中选择：

string spravaLOGY;
  private void nacitanie_logu()
  {
      MySqlConnection mcon = new MySqlConnection("Server=***;Database=OitDB;Uid=martin;Pwd=;");
      string s = "select sprava from logy where pc=@pc";
      mcon.Open();
      MySqlCommand mcd = new MySqlCommand(s, mcon);
      mcd.Parameters.AddWithValue("@pc", nazovPC);
      MySqlDataReader mdr = mcd.ExecuteReader();
      while (mdr.Read())
      {
          spravaLOGY = mdr.GetString("sprava");
      }
  }

插入，选择和调整工作正常但改变fontstyle不起作用。你有什么解决方案吗？ THX。