C#

private void FrmMain_Shown(object sender, EventArgs epp)
    {
    BackgroundWorker work = new BackgroundWorker();
    work.DoWork += Work_DoWork;
    work.ProgressChanged += Work_ProgressChanged;
    work.RunWorkerCompleted += Work_RunWorkerCompleted;
    work.WorkerReportsProgress = true;
    work.RunWorkerAsync("A parameter of any type you want to pass it");
    }

private void Work_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
    MyTextBox.Text = "Done.";
    }

private void Work_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
    MyTextBox.Text = ($"Progress: {e.ProgressPercentage} - {e.UserState as string}");
    }

private void Work_DoWork(object sender, DoWorkEventArgs e)
    {
    if (sender is BackgroundWorker work)
        {
        for (int i = 0; i < 1000000; i++)
            {
            Thread.Sleep(1000);
            work.ReportProgress(i / 10000, $"An object of any type you want to pass back to the main thread: {i}");
            }
        }
    }

for (int i = 0; i < 1000000; i++) {
   Thread.Sleep(1000);
   work.ReportProgress(i / 10000, $"An object of any type ...: {i}");
}