动态滚动到列表框中的焦点项目

Question

I have two list box in WPF which looks something like this:

Lets say, the left one is lbLeft and right one is lbRight.
The button adds one selected item from lbLeft to lbRight. And, removes the selected item form lbRight from the list.
The adds all the item from lbLeft to lbRight and clears lbRight. When I double click an item from lbLeft, it is added to the lbLeft and that newly added item is . Also, if i try to add an item from lbLeft which already exists in lbRight, it places a focus in that selected item(so that items are not repeated). But when lots of item are added in lbRight, I have to manually scroll down to the point where focus is placed. How can I make the scrolling of listbox automatic to the point where focus is placed?
I have done the following:

    private void select_Click(object sender, RoutedEventArgs e) // > button
    {
        addingItemToSelectedList();
    }

    private void remove_Click(object sender, RoutedEventArgs e) // < button
    {
        if (lbRight.SelectedItem != null) {
            lbRight.Items.RemoveAt(lbRight.SelectedIndex);
        }
    }

    private void selectall_Click(object sender, RoutedEventArgs e) // >> button
    {
        lbRight.Items.Clear();
        foreach (string item in column1) {
            lbRight.Items.Add(item);
        }

    }

private void lbLeft_MouseDoubleClick_1(object sender, MouseButtonEventArgs e)
    {
        addingItemToSelectedList();
    }
    private void addingItemToSelectedList() {
        if (lbLeft.SelectedItem != null)
        {
            string item = lbLeft.SelectedItem.ToString();
            addFocus(item);
        }
    }
    private void addFocus(string item) {
        if (!lbRight.Items.Contains(item))
        {
            lbRight.Items.Add(item);
            lbRight.SelectedIndex = lbRight.Items.Count - 1;
            lbRight.Focus();
        }
        else
        {
            int index = lbRight.Items.IndexOf(item);
            lbRight.SelectedIndex = index;
            lbRight.Focus();
        }
    }
    private void removeall_Click_1(object sender, RoutedEventArgs e) //<< button
    {
        lbRight.ItemsSource = null;
        lbRight.Items.Clear();
    }

column1 in the code is a list of items which populate lbLeft.

I tried to use lbRight.ScrollIntoView(lbRight.SelectedIndex); But it has no effect

Answer 1

ScrollIntoView() worked now. What i had to do was:
lbRight.ScrollIntoView(lbRight.Items[lbRight.SelectedIndex]);
It now passes the actual item rather than index of it.