WPF threads - can't access property/field

Question

Possible Duplicate:
The calling thread cannot access this object because a different thread owns it

I'm writing some thread handling in my app:

BackgroundWorkers()
{
    WorkerThread = new Thread(new ThreadStart(Loop));
    WorkerThread.SetApartmentState(ApartmentState.STA);
    WorkerThread.Start();
}

The called method is this one:

    public static void Loop()
    {
        while (true)
        {
            if (BackgroundWorkersTick != null)
            {
                BackgroundWorkersTick();
            }
            Thread.Sleep(30 * 1000);
        }
    }

in the "client" I use it this way:

BackgroundWorkers.BackgroundWorkersTick += new BackgroundWorkers.BackgroundWorkersTickHandler(Refresh);
...
private void Refresh()
{
    ViewDataCollection.GetData<TableViewData>().Tables = GameClient.ListTables();
    tablesListView1.SetItems(ViewDataCollection.GetData<TableViewData>().Tables);
    tablesListView1.Refresh();
}

TableListView inside has a method:

    public void Refresh() { ListItemContainer.Dispatcher.Invoke((Action)BindItems); }

    private void BindItems()
    {
        ListItemContainer.Children.Clear();
        foreach (TablesListViewItem item in items)
        {
            ListItemContainer.Children.Add(item);
        }
    }

iItems is defined as:

private List<TablesListViewItem> items;

In the line

ListItemContainer.Children.Add(item);

I'm getting exception of InvalidOperationException with message: The calling thread cannot access this object because a different thread owns it.

This whole code goes for WPF. I tried to switch to property, but no effect. I thought that the Dispatcher will do the work... What I'm doing wrong?

Without it, the app crash with message that only STA can get access to UI controls (or sth like this) — deha, Oct 16 '11 at 10:53
Try fetching the dispatcher like this - Application.Current.Dispatcher — Rohit Vats, Oct 16 '11 at 13:01

score 2 · Answer 1 · answered Oct 16 '11 at 15:54

Change the following lines

private void Refresh()
{
    ViewDataCollection.GetData<TableViewData>().Tables = GameClient.ListTables();
    tablesListView1.SetItems(ViewDataCollection.GetData<TableViewData>().Tables);
    tablesListView1.Refresh();
}

To

private void Refresh()
{
    Application.Current.Dispatcher.Invoke(new Action(()=>
    {
      ViewDataCollection.GetData<TableViewData>().Tables = GameClient.ListTables();
      tablesListView1.SetItems(ViewDataCollection.GetData<TableViewData>().Tables);
      tablesListView1.Refresh();
    }));
}

WPF threads - can't access property/field

1 Answers1