How to display the logged user in listbox c#

Question

So i have a login system and when the user logins a new form opens and i want the form to display the user Name. When user register he have to put his name and surname and that 2 things i want to be displayed in the new form that opens. So is there any easy way to put the logined user name into listbox?

so here is the registration code:

MySqlConnection dataConnection = new MySqlConnection();
        dataConnection.ConnectionString = "datasource=localhost;port=3306;username=root;password=";
        dataConnection.Open();
        MySqlTransaction transakcija = dataConnection.BeginTransaction();
        MySqlCommand dataCommand = new MySqlCommand();
        dataCommand.Connection = dataConnection;
        dataCommand.Transaction = transakcija;
        try
        {
            dataCommand.CommandText = "Insert INTO login.users (ime,upIme,geslo,dovoljenja) VALUES ('" + this.tB_Ime.Text + "','" + this.tB_upIme.Text + "','" + this.tB_geslo.Text + "', 'Navaden uporabnik')";
            dataCommand.CommandType = CommandType.Text;
            dataCommand.ExecuteNonQuery();
            transakcija.Commit();
            MessageBox.Show("Registracija uspešna!");
            this.Hide();
        }
        catch (Exception eks)
        {
            transakcija.Rollback();
            MessageBox.Show("Napaka pri registraciji\n" + eks.Message);
        }
        finally
        {
            dataCommand.Connection.Close();
        }
        Form1 f1 = new Form1();
        f1.ShowDialog();
        this.Close();

and login:

try
        {
            string myConnection = "datasource=localhost;port=3306;username=root;password=";
            MySqlConnection myConn = new MySqlConnection(myConnection);

            MySqlCommand SelectCommand = new MySqlCommand(" select * from login.users where upIme='" + this.tB_upIme.Text + "' AND geslo='" + this.tB_geslo.Text + "' ;", myConn);

            MySqlDataReader myReader;
            myConn.Open();
            myReader = SelectCommand.ExecuteReader();
            int count = 0;
            bool IsAdminUser = false;
            while (myReader.Read())
            {
                count = count + 1;
                IsAdminUser = myReader["dovoljenja"].Equals("Admin");
            }
            if (count == 1 && IsAdminUser == true)
            {
                MessageBox.Show("Prijavljeni ste kot administrator!");
                this.Hide();
                Form4 f4 = new Form4();
                f4.ShowDialog();
            }
            else if (count == 1)
            {
                MessageBox.Show("Uspešno ste se prijavili!");
                this.Hide();
                Form3 f3 = new Form3();
                f3.ShowDialog();
            }
            else if (count > 1)
            {
                MessageBox.Show("Dvojno uporabniško ime in geslo!");
                this.Hide();
            }
            else
                MessageBox.Show("Uporabniško ime ali geslo ni pravilno!");
            myConn.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

Answer 1

you can send the LoggedIn UserName to the UserForm constructor and from there you can add it to the required control.

Try This:

Login Form:

        string LoggedInUserName = String.Empty;
        while (myReader.Read())
        {
            count = count + 1;
            IsAdminUser = myReader["dovoljenja"].Equals("Admin");
            LoggedInUserName = myReader["FirstName"].ToString()+
                               myReader["LastName"].ToString();
        }
        if (count == 1 && IsAdminUser == true)
        {
            MessageBox.Show("Prijavljeni ste kot administrator!");
            this.Hide();
            Form4 f4 = new Form4(LoggedInUserName);
            f4.ShowDialog();
        }
        else if (count == 1)
        {
            MessageBox.Show("Uspešno ste se prijavili!");
            this.Hide();
            Form3 f3 = new Form3(LoggedInUserName);
            f3.ShowDialog();
        }

Now change the both admin form(Form4) and UserForm (Form3)

    //now change the Admin Form Form4 constructor to take 1 argument
    public Form4(string username)
    {
        InitializeComponent();
        myListBox.Items.Add(username);//Label1.Text= username;
    }

   //now change the UserForm Form3 constructor to take 1 argument
    public Form3(string username)
    {
        InitializeComponent();
        myListBox.Items.Add(username);//Label1.Text= username;
    }