2,000 Things You Should Know About WPF | Everything a WPF Developer Ne...

Normally, when you display a TreeView, the nodes are collapsed by default and the user clicks on the expander widgets to expand nodes that they want to look at.
You can expand all nodes in the TreeView by default by setting up an ItemContainerStyle for the TreeView and specifying that you want each TreeViewItem expanded....

You can define a custom data template for items in a TreeView, displaying any content you like in a panel, for each data item.
There’s a problem with doing this, however, if you want the container in the data template to stretch the entire width of the TreeView. In the sample below, we have a data template for a dog breed the displays data across three columns in a Grid. We...

I showed last time how to use a HierarchicalDataTemplate as the ItemTemplate for a TreeView. This allowed us to specify the look and feel of each node in the tree and also dictated how the main data item would be traversed to generate the tree.
If you have some hierarchical data in which the items are not all of the same type, you can specify more than one HierarchicalDataTemplate for the TreeView, based on the underlying type of each node....

If we just want each node in a TreeView control to contain text, we can use a single TreeViewItem in the HierarchicalDataTemplate and bind its Header property to the text that we want displayed. However, we can use an Panel we like in the data template...