The demo project prevents the TreeView from responding to keyboard input altogether. As a result, I could not customize the keyboard navigation for the TreeView. The TreeView's SelectedItem property does not have a setter. Unfortunately there is no supported way to programmatically set the selected item in a TreeView. I serialized the default TreeViewItem control template to XAML and then modified that until I got the result I was looking for. TipĬustomizing the ControlTemplate for the TreeViewItem class was easy once I discovered a little trick. Feel free to peruse that code (and all the rest of it) in the source code download, which is available at the top of this article. I am not going to discuss the code which populates the TreeView with dummy data. Let's take a look at the XAML for a Window which contains our customized TreeView: This step is a simple matter of setting the TreeView's ItemsPanel property to a Grid whose HorizontalAlignment is set to ' Center'. Doing so will provide symmetry between the items, as seen in the screenshot above. The final step is to make the TreeView center the root item(s) horizontally. Let's take a look at an abridged version of the typed Style: That setting was also applied in the typed Style mentioned previously. In order for the child items to be displayed in a horizontal row, I set the TreeViewItem.ItemsPanel property to a StackPanel with a horizontal orientation. In addition to customizing the TreeViewItem control template, you also must modify the ItemsPanel of TreeViewItem. The ItemsPresenter is used to display it's child items. The ContentPresenter is used to display the content of the item. The TreeViewItem control template should have two things: a ContentPresenter whose Name is 'PART_Header' and an ItemsPresenter. a Style with no Key) then it will automatically be applied to every TreeViewItem instance by default. If you wrap that template in a typed Style (i.e. The first step is to create a custom ControlTemplate for the TreeViewItem class. However, after we customize the way that TreeViewItems are rendered and how the TreeView positions its items, the same TreeView control can look like this: What you see above is certainly not a breathtaking representation of the data. If I populate a TreeView with some simple data and view it, by default it looks pretty plain. Graphical overviewīefore diving into the XAML which makes the magic happen, let's first take a look at what we are aiming to achieve. If you are interested in seeing another way that the TreeView can be customized, you might want to read Advanced Custom TreeView Layout in WPF. I also posted another article regarding layout customization for the TreeView control. It assumes that you already have knowledge of XAML, control templates, styles, triggers, hierarchical data templates, data binding, and other fundamentals of WPF. Along the way we will see how the power of templates and styles in WPF can provide incredible flexibility for customizing an application's user interface. The layout we will examine is quite similar to an "org chart", where each level of items is displayed in a horizontal row directly beneath their respective parent. / Interaction logic for MainWindow.This article discusses how to customize the item layout in a WPF TreeView. Instead, we use the HierarchicalDataTemplate, which allows us to template both the tree node itself, while controlling which property to use as a source for child items of the node.” As WPF Tutorial says in their website post TreeView, data binding and multiple templates “The WPF TreeView supports data binding, as pretty much all other WPF controls do, but because the TreeView is hierarchical in nature, a normal DataTemplate often won’t suffice.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |