MulticolumnTreeView

Hello Mindscape Team,

we are thinking about buying WPF Elements, but we need some special features:

• Selecting multiple items
• Drag and drop functionality for adding and moving nodes
• Different shortcuts for selecting rows, columns and fields (like excel)
• Sorting of nodes (within a part of the tree or within the complete tree)

1. Multiple selection.  We do not currently have this because the control is a TreeView which is single-select.  Implementing this would probably be a custom development: you could do this yourselves if you purchased the Enterprise licence (which includes source code), or we would be happy to discuss adding the feature for you.

2. Drag and drop.  We don't provide built-in support for this, but because we are a TreeView, the usual techniques for adding drag and drop to a WPF TreeView will work.  I keep meaning to do a blog post on this but here is the short form summary I have given to a couple of other people (it talks about dragging and dropping between MCTVs but the same techniques work for dragging and dropping within a single MCTV):

The basic idea is to handle the MouseDown (or MouseLeftButtonDown) event and call DragDrop.DoDragDrop from your event handler.  Then in the target control or controls, set AllowDrop="True" and handle the Drop event.  (To drag nodes within a treeview, just do this on the same treeview where you're initiating the drag.)

The main subtlety is getting hold of the tree view item in a databound (ItemsSource) scenario.  Here is the code that I used for this (where e is the MouseButtonEventArgs).
 

MulticolumnTreeViewItem tvi =

  (MulticolumnTreeViewItem)

    (mctv1.ContainerFromElement(e.OriginalSource as DependencyObject));

 
Your drop handler can similarly use e.OriginalSource (or hit testing) to determine where the object was dropped and to position it in the destination TreeView appropriately.  Again, you will probably be able to find sample code for a "normal" TreeView and reuse that.

3. Selection shortcuts.  Could you provide us with a bit more detail on what you want here?

4. Sorting.  You should be able to do this by sorting the default view of your source data: see ICollectionView.SortDescriptions, or ListCollectionView.CustomSort if you require more flexibility.