Simplifying the WPF TreeView by Using the ViewModel Pattern. Download the source code (requires Visual Studio 2008) - 28.6 KB Introduction This article explores how to use the ViewModel pattern to make it easier to work with the TreeView control in WPF.
Along the way, we examine why people often have difficulty with the WPF TreeView, what a ViewModel is, and two demo applications that show how to combine a TreeView with a ViewModel. One of the demos shows how to create a searchable TreeView, the other demonstrates how to implement lazy-loading (a.k.a. load-on-demand). Background of TreeView The TreeView control in WPF has gained an undeserved bad reputation. In Window Forms, it is very easy to use the TreeView control because it is dead simple. In contrast, the WPF TreeView is extremely flexible, inherently supports UI virtualization (i.e., TreeViewItems are created on-demand), allows for full visual customization, and has full support for data binding.
Background of ViewModel This makes it easier to create a user interface (UI) for the application. How to expand items in a TreeView – Part I. Oct 29, 2008 Exciting!
Yesterday, the new Silverlight Toolkit (the team I now work for) was made available in CodePlex. This was announced by Scott Guthrie in his PDC keynote and by my manager Shawn Burke in his blog. We created the Silverlight Toolkit to provide developers with a set of reusable components that maximize productivity and help take Silverlight to the next level. The toolkit is available under the Microsoft Public License, so we provide the full source code (as well as tests and samples), and encourage you to reuse our code in your applications. If you want to know more about it, I recommend that you check out our web site, download the toolkit, and post questions in the Silverlight controls forum. Expanding items in a TreeView Among many other controls, we shipped a Silverlight TreeView, nearly identical to the WPF one.
In WPF, this can be done by adding an implicit style to the resources of your page: Couldn’t be any easier. Silverlight ImplicitStyleManager Auto OneTime None. Complex Hierarchical Data Templates. WPF TreeView mittels HierarchicalDataTemplate bauen @CODEKICKER. WPF Tutorial - Dynamic Data and the TreeView. One WPF control that we haven't taken a look at here on SOTC is the TreeView.
Well, no more! Today we are going to rectify that, as we build an application that not only uses the TreeView, but also dynamically loads data into it on demand. We are going to cover a couple other new topics as well, including HierarchicalDataTemplates and CompositeCollections. So what are we building? A pretty simple app that pulls the tree hierarchy of categories and images from Gaming Textures and displays it in a TreeView. For example, we start out with the list of base categories: When an item is expanded, we send off a request for the children: And once we have the children, we display them (complete with helpful tooltips!)
Ok, so how do we do this? This gives up a basic layout that looks like this: Just by looking at that code snippet, you have probably already figured out the basics of using a TreeView. But what if we do get the data back correctly (which hopefully we do)? And that is it! Source Files: TreeView in WPF. Introduction A TreeView represents data in a hierarchical view in a parent child relationship where a parent node can be expanded or collapse.
The left side bar of Windows Explorer is an example of a TreeView. The TreeView tag represents a WPF TreeView control in XAML. The Width and Height properties represent the width and the height of a TreeView. The Name property represents the name of the control, which is a unique identifier of a control. The following code snippet sets the name, height, and width of a TreeView control. <TreeView Margin="10,10,0,13" Name="TreeView1" HorizontalAlignment="Left" VerticalAlignment="Top" Width="194" Height="200" /> Adding TreeView Items A TreeView control hosts a collection of TreeViewItem.
VerticalAlignment="Top" Width="194" Height="200"> By default, the parent node is collapsed but when you click on it, the expanded view looks like Figure 1. Figure 1. Adding TreeView Items Dynamically Let's change our UI and add a TextBox and a button control to the page.
WPF TreeView mittels HierarchicalDataTemplate bauen @CODEKICKER. Simplifying the WPF TreeView by Using the ViewModel Pattern.