Threads

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ControleGeral_DB;
using System.Threading;

namespace ControleGeral
{
    public partial class Logar : Form
    {
        private MainMDI mdi;
        
        public Logar(MainMDI mdi)
        {
            InitializeComponent();
            this.mdi = mdi;
            
        }

        private void bLogar_Click(object sender, EventArgs e)
        {
            Thread thread = new Thread(new ThreadStart(logar));
            Thread threadBar = new Thread(new ThreadStart(bar));
            thread.Start();
            threadBar.Start(); 
        }

        private void bar()
        {
            barra.Value = 50;
        }

        private void logar()
        {
            try
            {
                Loggin.start(tUsuario.Text, tSenha.Text, BS.Util.Conf.Conf.Instance.getValue("database"), BS.Util.Conf.Conf.Instance.getValue("ip"));
            }
            catch (System.Exception exception)
            {
                MessageBox.Show("Nome de usuário ou senha inválida!");
                return;
            }

            MessageBox.Show("Bem vindo " + tUsuario.Text + "!");
            mdi.Text = "Controle Geral - BS Soluções Tecnológicas #" + tUsuario.Text + "";
            this.Close();
        }

        
    }
}

barra.Value = 50;

mdi.Text = "Controle Geral - BS Soluções Tecnológicas " + tUsuario.Text + "";

 this.Close();