private void ViewModelOnCatalogNavigated(object sender, bool forwardNavigation)
{
if (forwardNavigation)
{
return;
}
ItemsControl.Visibility = Visibility.Collapsed;
_scrollViewer.ScrollToVerticalOffset(0);
if (ItemsControl.ItemsSource == null || _navigationDataContexts.Count == 0)
{
ItemsControl.Visibility = Visibility.Visible;
return;
}
var dataContext = _navigationDataContexts.Pop();
// a little bit magic
Dispatcher.BeginInvoke(() =>
{
try
{
ItemsControl.BringIntoView(dataContext);
_scrollViewer.ScrollToVerticalOffset(_scrollViewer.VerticalOffset - _navigationVerticalOffsets.Pop());
}
catch (Exception)
{
}
ItemsControl.Visibility = Visibility.Visible;
});
}
public async Task <TreeViewItem> GetItemAsync(TModel node, IList <TModel> rootNodes)
{
Stack <TModel> nodes = new Stack <TModel>();
//首先把结点从子到父放进一个站里，栈顶将是根节点
while (!rootNodes.Contains(node))
{
nodes.Push(node);
if (GetParent(node) == null)
{
throw new Exception("树型数据有误");
}
node = GetParent(node);
}
ItemsControl treeViewItem = TreeView;
while (true)
{
//获取该项对应的视图
treeViewItem = treeViewItem.ItemContainerGenerator
.ContainerFromItem(node) as TreeViewItem;
if (treeViewItem == null)
{
return(null);
}
if (nodes.Count == 0)
{
//说明已经获取到了目标Item
return(treeViewItem as TreeViewItem);
}
node = nodes.Pop();
treeViewItem.BringIntoView();
(treeViewItem as TreeViewItem).IsExpanded = true;
await WaitForContainersGenerated(treeViewItem.ItemContainerGenerator);
}
}
public bool FocusOnNode(IDurable focusRange)
{
if (focusRange == null)
{
return(false);
}
if (EventTreeView == null)
{
return(false);
}
if (EventTreeView.ItemsSource == null)
{
return(false);
}
List <BaseTreeNode> treePath = new List <BaseTreeNode>();
foreach (var node in EventTreeView.ItemsSource)
{
BaseTreeNode baseTreeNode = node as BaseTreeNode;
if (baseTreeNode == null)
{
continue;
}
baseTreeNode.ForEach((curNode, level) =>
{
EventNode treeEventNode = curNode as EventNode;
if (treeEventNode == null)
{
return(true);
}
if (treeEventNode.Entry.Start > focusRange.Finish)
{
return(false);
}
if (treeEventNode.Entry.Contains(focusRange))
{
treePath.Add(curNode);
//find desired node in tree
if (treeEventNode.Entry.Start >= focusRange.Start && treeEventNode.Entry.Finish <= focusRange.Finish)
{
return(false);
}
}
return(true);
});
ItemsControl root = EventTreeView;
int pathElementsCount = treePath.Count;
if (pathElementsCount > 0)
{
//expand path in tree
int index = 0;
for (index = 0; index < (pathElementsCount - 1); index++)
{
BaseTreeNode expandNode = treePath[index];
if (root != null)
{
root = root.ItemContainerGenerator.ContainerFromItem(expandNode) as ItemsControl;
}
treePath[index].IsExpanded = true;
}
BaseTreeNode finalNode = treePath[index];
// select target node
finalNode.IsExpanded = false;
finalNode.IsSelected = true;
// focus on finalNode
if (root != null)
{
root = root.ItemContainerGenerator.ContainerFromItem(finalNode) as ItemsControl;
if (root != null)
{
root.BringIntoView();
}
}
EventTreeView.InvalidateVisual();
return(true);
}
}
return(false);
}
