![]() The CustomControl automatically databound ListBoxes together: each ListBox’s ItemsSource property is databound to the SelectedItem’s children property of the previous ListBox in the visual tree.This property indicates the number of ListBox that should be generated. The CustomControl has a Depth property of type int.This ItemsControl has its ItemTemplate property set to a DataTemplate containing a ListBox. In the template of this CustomControl is an ItemsControl.I create a new CustomControl which inherits Control (I couldn’t use neither Selector or TreeView because I wouldn’t have been able to manage the SelectedItem property from the derived class).The solution I finally choose involves creating multiple ListBox and wire them together using DataBinding: I though at the beginning that playing with the templates of the TreeView and TreeViewItem would do the trick but it didn’t. I asked a question on StackOverflow about this control because I didn’t find any easy way to do it. To understand what I mean, I wanted to change the layout of this: Once again the solution is data binding, which we'll look into in the next chapters.Last week at work I was requested to create a new control which should have the behavior of the WPF treeview with a template involving multiple ListBox. 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.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |