Treeview wpf example4/14/2024 Another technique that has better performance is to search the data model for the specified object, keep track of its location within the data hierarchy, and then find the corresponding TreeViewItem in the TreeView. The following example works for any TreeView, regardless of the underlying data model, and searches every TreeViewItem until the object is found. This example also works if the TreeView does not use virtualized items. The example ensures that each TreeViewItem is instantiated so that its child items can be searched. The following example searches a TreeView for a specific object and returns the object's containing TreeViewItem. In the case where items might be virtualized, you also must realize a TreeViewItem to check whether it contains the data object. The items in a TreeView can also be virtualized to improve performance. To find a TreeViewItem that contains a specific data object, you must traverse each level of the TreeView. For example, you may need to programmatically expand the TreeViewItem, or select a different item in the TreeView. It is typically best to work with the underlying data object, but sometimes you may need to programmatically manipulate the data's containing TreeViewItem. If your TreeView is bound to a data source, the SelectedItem property provides a convenient way for you to quickly retrieve the selected data object. Once again the solution is data binding, which we'll look into in the next chapters.The TreeView control provides a convenient way to display hierarchical data. Situations, and while you could do it from Code-behind instead, this would have resulted in even more lines of code. While it is entirely possible to define an entire TreeView just using markup, as we did in the above examples, it's not the best approach in most Because we're defining the entire thing with simple markup, you can do almost anything, but as you can see from the example code, it doesĬome with a price: Huge amounts of XAML code, for a tree with just six nodes in total! Summary I did a whole bunch of things here, just to show you the kind of flexibility you get: I colored the child items and I added images and even buttons to the You're rewarded with a lot more flexibility than you could ever get from the WinForms TreeView. With the WPF TreeView, it's a bit more complex, but This is very easy to do with WinForms, because the TreeView is built exactly for this scenario. One of the common requests from people coming from WinForms or even other UI libraries is the ability to show an image next to the text label of a TreeView Shows us that we can stuff pretty much whatever we want to into the Header property instead of just a string and then have the TreeView render it - a greatĮxample of why it's so easy to customize the look of WPF controls. As you can see, I can just specify a text string and then have it rendered directly withoutĭoing anything else, but this is WPF being nice to us - internally, it wraps the text inside of a TextBlock control, instead of forcing you to do it. The Header is an interesting property, though. TreeViewItem's with images and other controls By default, a TreeViewItem is not expanded, but to show you the structure of the example, I have used the IsExpanded property to expand the two parent items. To specify the text we want displayed for each node, we use the Header property. The TreeView control and its child objects are also child tags to its parent object. We simply declare the TreeViewItem objects directly in the XAML, in the same structure that we want to display them in, where the first tag is a child of This is indeed very easy to get started with, as you can see from the example here: The TreeView control: A simple TreeView exampleĪs we talked about in the previous article, the WPF TreeView can be used in a very simple manner, by adding TreeViewItem objects to it, either fromĬode-behind or simply by declaring them directly in your XAML.
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