Question

I am creating a form in c# so any new form inheritances the property of build in class From
I also created a class called program which starts a connection to my Database I would like all my forms to inherit it because I don’t want to open a new connection for every form
i cant use interface because program contains main() where it creates a connection
My program class is

      class Program
      {
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {

        MySqlConnection myConnection = new MySqlConnection("Server=instance2813231.db.xeround.com;Port=18422;Database=shares info;Uid=user;Pwd=password;");
        MySqlCommand command = myConnection.CreateCommand();

        try
        {

            myConnection.Open();
            MessageBox.Show("connected");


        }
        catch (Exception a)
        {
            Console.WriteLine(a.ToString());
            MessageBox.Show("Failed");
        }
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}

How can I get around this?

Answer 1

I would like all my forms to inherit it

Ick, don’t. It’s an abuse of inheritance in order to achieve code reuse in a very poor way.

Firstly, try to separate your GUI code from your database code.

Secondly, favour composition over inheritance – a form isn’t logically a Program or a “database connection opener”. It should use the latter, but it isn’t one. You should have a single entry point, which instantiates whatever it needs to, then starts things running.

Thirdly, don’t use a single connection through your code – instead, open and close connections as you need to, and let connection pooling take care of the efficiency aspect.

So instead of deriving from the class, provide each form with a reference to an instance of your database connection opener (if you really want to mix your database and GUI code… ick), and then your form can use that opener.