winforms C# .NET - How to Improve the Performance of my code while using loops(for ,foreach, etc...)

Question

Closed. This question needs to be more focused. It is not currently accepting answers. question from:https://stackoverflow.com/questions/65947473/winforms-c-sharp-net-how-to-improve-the-performance-of-my-code-while-using-lo

Answer 1

You do not seem to need the for cycle at all. And the MaxIndex either. Just download the records for the time and mark buttons.

private void SomeMethod(string Day, string Time)
{
    HashSet<string> classNumbers = new HashSet<string>();

    string str = "select [classroom Number] from Table where [Day] = @ParamDay and [Time] = @ParamTime";
    using (OleDbCommand Command = new OleDbCommand(str, Connection))
    {
        Command.Parameters.Add("@ParamDay", Day);
        Command.Parameters.Add("@ParamTime", Time);                
        Connection.Open();
        using (OleDbDataReader reader = Command.ExecuteReader(CommandBehavior.CloseConnection))
        {
            while (reader.Read())
            {
                classNumbers.Add(reader["classroom Number"].ToString());
            }
        }
    }

    foreach (Button btn in ButtonsPanel.Controls)
    {
        if (classNumbers.Contains(btn.Text))
        {
            btn.BackColor = Color.Red;
        }
    }
}