GenerateNext() private method

private GenerateNext ( bool &isNewlyRealized ) : DependencyObject
isNewlyRealized bool
return DependencyObject
コード例 #1
0
        void AddItemsToPresenter(GeneratorPosition position, int count)
        {
            if (_presenter == null || _presenter._elementRoot == null || _presenter._elementRoot is VirtualizingPanel)
            {
                return;
            }

            Panel panel    = _presenter._elementRoot;
            int   newIndex = ItemContainerGenerator.IndexFromGeneratorPosition(position);

            using (var p = ItemContainerGenerator.StartAt(position, GeneratorDirection.Forward, true))
                for (int i = 0; i < count; i++)
                {
                    var item = Items [newIndex + i];
                    DependencyObject container = null;

                    bool fresh;
                    container = ItemContainerGenerator.GenerateNext(out fresh);
                    ContentControl c = container as ContentControl;
                    if (c != null)
                    {
                        c.ContentSetsParent = false;
                    }

                    FrameworkElement f = container as FrameworkElement;
                    if (f != null && !(item is FrameworkElement))
                    {
                        f.DataContext = item;
                    }

                    panel.Children.Insert(newIndex + i, (UIElement)container);
                    ItemContainerGenerator.PrepareItemContainer(container);
                }
        }
コード例 #2
0
        void UpdateDisplayedItem(object selectedItem)
        {
            object content;

            // Can't do anything with no content presenter
            if (_contentPresenter == null)
            {
                return;
            }

            // Return the currently displayed object (which is a UIElement)
            // to its original container.
            if (DisplayedItem != null)
            {
                content = _contentPresenter.Content;
                DisplayedItem.Content = content;
                DisplayedItem         = null;
            }
            _contentPresenter.Content = null;

            if (selectedItem == null)
            {
                _contentPresenter.Content         = NothingSelectedFallback;
                _contentPresenter.ContentTemplate = null;
                SelectionBoxItem         = null;
                SelectionBoxItemTemplate = null;
                return;
            }

            // If the currently selected item is a ComboBoxItem (not ListBoxItem!), we
            // display its Content instead of the CBI itself.
            content = selectedItem;
            if (content is ComboBoxItem)
            {
                content = ((ComboBoxItem)content).Content;
            }

            // Only allow DisplayedItem to be non-null if we physically move
            // its content. This will only happen if DisplayedItem == SelectedItem
            DisplayedItem = ItemContainerGenerator.ContainerFromIndex(SelectedIndex) as ComboBoxItem;

            SelectionBoxItem         = content;
            SelectionBoxItemTemplate = ItemTemplate;

            // If displayed item is avaiable, we can get the right template from there. Otherwise
            // we need to create a container, read the template and destroy it.
            if (DisplayedItem != null)
            {
                SelectionBoxItemTemplate = DisplayedItem.ContentTemplate;
                if (content is UIElement)
                {
                    DisplayedItem.Content = null;
                }
                else
                {
                    DisplayedItem = null;
                }
            }
            else
            {
                bool         fresh;
                ComboBoxItem container = ItemContainerGenerator.ContainerFromIndex(SelectedIndex) as ComboBoxItem;
                if (container == null)
                {
                    var index = ItemContainerGenerator.GeneratorPositionFromIndex(SelectedIndex);
                    using (ItemContainerGenerator.StartAt(index, GeneratorDirection.Forward, true))
                        container = ItemContainerGenerator.GenerateNext(out fresh) as ComboBoxItem;
                    ItemContainerGenerator.PrepareItemContainer(container);
                }
                SelectionBoxItemTemplate = container.ContentTemplate;
            }

            _contentPresenter.Content         = SelectionBoxItem;
            _contentPresenter.ContentTemplate = SelectionBoxItemTemplate;
        }