C#

public void Init(BindingList<Produkt> _produktLst)
{
    produktLst = _produktLst;
    namnCbx.DataSource = produktLst;
    namnCbx.DisplayMember = "Namn";
    namnCbx.ValueMember = "Namn";
}

private void namnCbx_TextChanged(object sender, EventArgs e)
{
    RunFilter();
}

private void RunFilter()
{
    BindingList<Produkt> filteredLst;

    if (namnCbx.Text.Length == 0) // Om fältet är tomt
    {
        namnCbx.DataSource = produktLst;
    }
    else // Om det finns kriterier att filtrera på
    {
        filteredLst = new BindingList<Produkt>(produktLst.Where(delegate(Produkt p)
            {
                if (!p.Namn.Contains(namnCbx.Text))
                    return false;
                else
                    return true;
            }
        ).ToList());

        namnCbx.DataSource = filteredLst;
        if(namnCbx.Focused)
            namnCbx.DroppedDown = true;
    }
}
}

static string sampleFile = @"C:\Projects\Sandbox\Async1\Async1\somefile.txt";

static void Main(string[] args)
{
    Console.WriteLine("Task 1 started");

    Task task = new Task(ReadTheFile);
    task.Start();
    task.Wait();


    Console.WriteLine("The READ task was started");
    Console.ReadLine();
}

static void ReadTheFile()
{
    int count = 0;

    using (StreamReader reader = new StreamReader(sampleFile))
    {
        Console.WriteLine("Reading the file XXXX.");
        string v = reader.ReadToEnd();

        count += v.Length;
    }

    Console.WriteLine("Count: " + count);
}

static void Main(string[] args)
{
    Console.WriteLine("Task 1 started");

    Task task = new Task(ProcessDataAsync);
    task.Start();
    task.Wait();


    Console.WriteLine("The READ task was started");
    Console.ReadLine();
}


static async void ProcessDataAsync()
{
    Task<int> task = HandleFileAsync(sampleFile);

    Console.WriteLine("Getting ready to read the file.");

    int x = await task;
    Console.WriteLine("Count: " + x);
}


static async Task<int> HandleFileAsync(string file)
{
    Console.WriteLine("HandleFile enter");
    int count = 0;

    using (StreamReader reader = new StreamReader(file))
    {
        Console.WriteLine("Reading the file.");
        string v = await reader.ReadToEndAsync();

        count += v.Length;
    }

    Console.WriteLine("HandleFile exit");
    return count;
}

// UserControl1 :| 
{
private void textBox1_TextChanged(object sender, EventArgs e)
{
_titleText = textBox1.Text;
this.titleChanged += new TitleChangedHAndler(UserControl2.onTitleChanged);
if (titleChanged != null)
{
titleChanged(_titleText);
}
}
}
// UserControl2
private void paint(object sender, PaintEventArgs e)
{
drawString(Text,...);
}
public void onTitleChanged(text)
{
Text = text;
this.Invalidate();

}