如何在C＃中将scroollbar添加到组合框项目

Question

I am working on silverlight using c#. I have to display the combo items in a scrollbar.

My attempt to do this is:

            TextBlock txtblkName = generateTextBlock();
            ComboBox cb = new ComboBox();
            ScrollViewer scrollViewer = new ScrollViewer();

            cb.Width = 45;
            cb.Height = 20;
            foreach (String item in param.Component.Attributes.Items)
            cb.ItemsSource = param.Component.Attributes.Items;
            scrollViewer.Content = cb;
            scrollViewer.HorizontalAlignment = HorizontalAlignment.Center;
            scrollViewer.VerticalAlignment = VerticalAlignment.Center;
            scrollViewer.ScrollToVerticalOffset(3);
            cb.SelectionChanged += (o, e) =>
            {
                txtblkName.Text = cb.SelectedValue.ToString() + " " + param.Unit;
            };
            cb.SelectedIndex = param.Component.Attributes.Selected != -1 ? param.Component.Attributes.Selected : 0;
            Grid.SetColumn(scrollViewer, 1);
            childGrid.Children.Add(scrollViewer);

which results in scroll over combo box .Like this:

Not on it's item displayed by scrollbar . Could some one please help me to create scrollbar only on items displayed not on all combo box?

Answer 1

You dont need ScrollViewer here, If you need Scrollbar for your comboboxItems set this property MaxDropDownHeight to some value

        ComboBox cb = new ComboBox();
        List<string> items = new List<string>();
        items.Add("1");
        items.Add("2");
        items.Add("3");
        items.Add("5");
        items.Add("7");
        items.Add("8");
        cb.ItemsSource = items;
        cb.MaxDropDownHeight = 20;
        childGrid.Children.Add(cb);