public IndexFromContainer ( DependencyObject container ) : int | ||
container | DependencyObject | |
Результат | int |
/// <summary> /// Sets focus to the next item in the ContextMenu. /// </summary> /// <param name="down">True to move the focus down; false to move it up.</param> private void FocusNextItem(bool down) { int count = Items.Count; int startingIndex = down ? -1 : count; MenuItem focusedMenuItem = FocusManager.GetFocusedElement() as MenuItem; if (null != focusedMenuItem && (this == focusedMenuItem.ParentMenuBase)) { startingIndex = ItemContainerGenerator.IndexFromContainer(focusedMenuItem); } int index = startingIndex; do { index = (index + count + (down ? 1 : -1)) % count; MenuItem container = ItemContainerGenerator.ContainerFromIndex(index) as MenuItem; if (null != container) { if (container.IsEnabled && container.Focus()) { break; } } }while (index != startingIndex); }
/// <summary> /// This is the method that responds to the KeyDown event. /// </summary> /// <param name="e"></param> protected override void OnKeyDown(KeyEventArgs e) { TabItem nextTabItem = null; // Handle [Ctrl][Shift]Tab, Home and End cases // We have special handling here because if focus is inside the TabItem content we cannot // cycle through TabItem because the content is not part of the TabItem visual tree int direction = 0; int startIndex = -1; switch (e.Key) { case Key.Tab: if ((e.KeyboardDevice.Modifiers & ModifierKeys.Control) == ModifierKeys.Control) { startIndex = ItemContainerGenerator.IndexFromContainer(ItemContainerGenerator.ContainerFromItem(SelectedItem)); if ((e.KeyboardDevice.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift) { direction = -1; } else { direction = 1; } } break; case Key.Home: direction = 1; startIndex = -1; break; case Key.End: direction = -1; startIndex = Items.Count; break; } nextTabItem = FindNextTabItem(startIndex, direction); if (nextTabItem != null && nextTabItem != SelectedItem) { e.Handled = nextTabItem.SetFocus(); } if (!e.Handled) { base.OnKeyDown(e); } }
private void SetRangeSelection(ListBoxItem item) { int itemIndex = ItemContainerGenerator.IndexFromContainer(item); int selectionAnchorIndex = ItemContainerGenerator.IndexFromContainer(selectionAnchor); int rangeStartIndex = itemIndex.Min(selectionAnchorIndex); int rangeEndIndex = itemIndex.Max(selectionAnchorIndex); for (int i = 0; i < ItemContainerGenerator.ItemsCount; i++) { DependencyObject itemContainer = ItemContainerGenerator.Generate(i); itemContainer.SetCurrentValue(Selector.IsSelectedProperty, rangeStartIndex <= i && i <= rangeEndIndex); } }
private int ElementIndex(ListBoxItem listItem) { return(ItemContainerGenerator.IndexFromContainer(listItem)); }
/// <summary> /// Called by ListBoxItem instances when they get focus /// </summary> /// <param name="listBoxItemNewFocus">ListBoxItem that got focus</param> internal override void NotifyListItemGotFocus(ListBoxItem listBoxItemNewFocus) { // Track the focused index _focusedIndex = ItemContainerGenerator.IndexFromContainer(listBoxItemNewFocus); }
// update container and index with current values internal ItemInfo Refresh(ItemContainerGenerator generator) { if (Container == null && Index < 0) { Container = generator.ContainerFromItem(Item); } if (Index < 0 && Container != null) { Index = generator.IndexFromContainer(Container); } if (Container == null && Index >= 0) { Container = generator.ContainerFromIndex(Index); } if (Container == SentinelContainer && Index >= 0) { Container = null; // caller explicitly wants null container } return this; }