FileSystemWatcher + Dialog

I wanna show a dialog everytime some file has been changed... But everytime that dialog shows up, my app freeze. How can I do this with another thread? Any ideas?

protected virtual void CreateWatcher (object path)
{
    if (watcher != null)
    {
        watcher.EnableRaisingEvents = false;
        watcher.Dispose ();
    }

    //Create a new FileSystemWatcher. 
    watcher = new FileSystemWatcher ();

    //Set the filter to only catch TXT files. 
    watcher.Filter = "*.txt";
    watcher.IncludeSubdirectories = true;
    watcher.NotifyFilter = NotifyFilters.LastWrite;

    //Subscribe to the Created event.
    watcher.Changed += new FileSystemEventHandler (OnChanged);
    watcher.Created += new FileSystemEventHandler (OnChanged);
    //watcher.Deleted += new FileSystemEventHandler (OnChanged);
    //watcher.Renamed += new RenamedEventHandler (OnRenamed);

    //Set the path to C:\\Temp\\ 
    watcher.Path = @path.ToString();

    //Enable the FileSystemWatcher events. 
    watcher.EnableRaisingEvents = true;
}
void OnChanged (object source, FileSystemEventArgs e)
{
    NovaInteracaoMsg();
    }

protected virtual void NovaInteracaoMsg ()
{
    novaInteracao = new MessageDialog (this, DialogFlags.DestroyWithParent, MessageType.Question, ButtonsType.YesNo, "Foi detectada a mudança nos arquivos do modelo. Deseja inserir uma nova interação?");
    ResponseType result = (ResponseType)novaInteracao.Run ();

    if (result == ResponseType.Yes) {
        OpenInfoWindow (novaInteracaoPath);
        return;
    }
    else {
        novaInteracao.Destroy ();
    }
}

void OnRenamed (object source, RenamedEventArgs e)
{
    //Console.WriteLine ("File: {0} renamed to\n{1}", e.OldFullPath, e.FullPath);
    }

protected virtual void OpenInfoWindow (string path)
{
    ModMemory.Iteration iterWin = new ModMemory.Iteration (path);
    iterWin.Modal = true;
    iterWin.Show ();

    iterWin.Destroyed += delegate {
        // TODO: Funções para executar quando a janela for fechada
        // 开发者_JS百科Possivelmente atualizar o número de interações realizadas
        Console.WriteLine ("Janela modal destruída");           
    };
}

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The problem is that you are already using another thread. Try one of the following approaches

1. Set the FileSystemWatcher.SynchronizingObject property so it raises events on your UI thread. Now you can show a UI that won't freeze or
2. Use Control.BeginInvoke() in the event handler.

This was a psychic debugging attempt, there was nothing in your question that helped me be sure that's the correct answer.

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Call Show() instead of ShowDialog() in your form.

http://msdn.microsoft.com/en-us/library/system.windows.forms.control.show.aspx

Edit - MessageBox classes are Modal, if you want a modeless dialog window you'll have to create it yourself.