TreeListView - A Multi-Column Variant of TreeListBox

by Avatar Bill Henning (Actipro)
Thursday, July 14, 2016 at 6:49pm


In the last blog post on our TreeListBox control development, we announced that the TreeListBox control was ready for closed alpha testing.  TreeListBox is a new control that has much of the same functionality as the tree control found in the Visual Studio Solution Explorer.

In today's post, I'd like to announce a new TreeListView control that is now also ready for alpha testing.  The TreeListView control is a multi-column variant of the TreeListBox control that renders similar to a standard ListView but has all the tree and advanced features found in TreeListBox.


The animation above shows several of the features found in this new control such as node expansion, column resizing, column reordering, column header context menus, and more.

Feature Progress

Thus far these TreeListView features have been completed:

  • All features found in TreeListBox.
  • Templates, template selectors, or text property bindings used to specify custom content for each cell.
  • Column width can be a specific pixel value, auto (size to header, cells, or both), or star-sized.
  • Optional minimum and maximum widths for column auto/star-sizing modes.
  • Columns can optionally be resized, reordered, and have visibility toggled by the end user.
  • Frozen columns that don't scroll horizontally.
  • Set which column renders the indentation and expander buttons.
  • Column headers have a built-in context menu, and the headers themselves can be hidden.
  • Size columns to fit contents.
  • Optional grid line display.
  • Numerous events for column resizing, reordering, visibility changes, and header menu requests.


If you would like to start working with either of the controls and provide us with feedback, please write our support address or chat with us on Slack to sign up for testing.  Now is the time to contribute your additional feature ideas and report bugs.  Anyone who has a WPF Studio license is fully licensed to use the control in their apps.

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Actipro Blog 2016 Q2 Posting Summary

by Avatar Bill Henning (Actipro)
Friday, July 1, 2016 at 3:05pm


What We Accomplished

In this quarter, we published new maintenance releases of all our control products and released the 2016.1 WinForms Controls.  In terms of development, we've been working on a new Grids product (for WPF and UWP) that will initially consist of a TreeListBox, similar to the tree control found in the Visual Studio Solution Explorer.  That control is already in alpha testing to some customers.  While that testing is ongoing, we have made great progress on a TreeListView control, which is a multi-column variant of the TreeListBox control.  This control features everything you find in a standard ListView, along with all the features of TreeListBox, and additional ones like column reordering, frozen columns, etc.  We'll post more on this new control very soon.

What’s Coming Next

Development of the TreeListView control is currently the primary focus.  We hope to wrap that up for alpha testing in the next two or three weeks.  After that we have some other plans for derived controls that are based on the foundation provided by TreeListBox and TreeListView that we will be getting into.

Blog Post List

Control Product Development

Control Product Releases

WinForms Controls 2016.1 Released

by Avatar Bill Henning (Actipro)
Wednesday, June 1, 2016 at 8:00pm


A new version of our Windows Forms controls has been released.  This version includes several large new features along with numerous minor bug fixes and updates.  First, these are some of the major new features…

Floating Documents


When a new DockManager property is set to true, documents can be floated to their own window.  This allows them to be moved to and maximized on a second monitor.

Document Layout Serialization

We've always had layout serialization for tool windows but now tabbed document windows can have their layouts serialized as well.

C# Parser Updated to Support C# 5.0 Syntax

The C# parser in the WinForms .NET Languages Add-on has been updated to support the parsing of C# 5.0 syntax.

See the announcement post for the detailed list of other enhancements and updates.

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TreeListBox - New Features and Ready for Alpha Testing

by Avatar Bill Henning (Actipro) - 1 comment
Monday, May 23, 2016 at 3:52pm


In the last blog post on our TreeListBox control development, we talked about new features like async loading and inline editing that were added.  In today's post, we'll talk about some more new features and we're also announcing that the alpha test of this control is now ready.

If you would like to start working with the control and provide us with feedback, please write our support address or chat with us on Slack to sign up for testing.  Now is the time to contribute your additional feature ideas and report bugs.  Anyone who has a WPF Studio license is fully licensed to use the control in their apps.

New Features

Since our new post, we've continued to enhance the control and add new features.  First, you now can optionally display the root item in the control.  When you choose not to do so (the default), the root node's children will be the top-level items.

There is now more control over expandability and when children are queried.

A robust drag and drop system supports dragging to external controls, dragging and dropping on the same control, and dropping from external controls.  You have full control over the visual feedback that is provided and what happens when a drop executes.

The control supports data virtualization when virtualized lists of child items are used.  With data virtualization, it's possible to support paged retrieval of items as they are requested for display.

A couple new options determine how far items are indented based on their depth.

Feature Progress

Thus far these features have been completed ( marks new features since the last post):

  • Fully customize the appearance of each node.
  • UI virtualization, allowing for hundreds of thousands of nodes to be loaded into a tree very quickly.
  • No scrollbar jumpiness as seen in other virtualized tree controls when scrolling vertically.
  • Use your own custom data models as the source for the tree, with no dependencies on UI or our interfaces. An adapter class is used (and can be fully customized to fit your model) to communicate between the UI and the model for things like expansion state, getting children, etc.
  • The adapter can be coded with bindings in XAML (convenient, yet can be slow in very large trees) or via method overrides (slightly more work but lightning fast).
  • Optionally show the root item in the control.
  • Fine-grained control over expandability and children query triggers.
  • Optional async loading with busy indicator display.
  • Events for expansion.
  • Events for selection.
  • Single or multi-selection, with Ctrl and Shift-based selection options.
  • Filter selection such as only allowing sibling nodes to be multi-selected, or nodes of the same depth.
  • All common tree hotkeys supported including special ones for expanding and collapsing entire branches.
  • Select or ensure nodes are visible by path.
  • Double-click and Return key default action handling.
  • Optional checkboxes within the data templates.
  • Intelligent text searching so when you start typing while the control has focus, it will auto-focus the item that matches the typed text.
  • Inline editing via F2 and single-click on a selected item.
  • Per-item context menus that can be constructed dynamically via an event.
  • Drag items to external controls, drop data from external controls, or drag/drop items within the control itself.
  • Dragged items can highlight above, on, and below drop areas for each item.
  • Single and multiple item dragging is supported.
  • Optional data virtualization optimization when using virtualized collections.
  • Indentation of top-level and other nodes can be set independently.


The TreeListBox control is now ready for alpha testing.  Please contact us via our ticket system or in Slack to sign up for testing and send in your feedback.  We will continue to refine the API based on your feedback before a future final release.

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WPF, UWP, and Silverlight v2016.1 Maintenance Releases

by Avatar Bill Henning (Actipro)
Friday, May 13, 2016 at 7:19pm


Maintenance releases of our v2016.1 WPF, Universal Windows, and Silverlight controls have been released and are now available for download.

Docking/MDI for WPF and UWP has several new options that give you more control over UI appearance.  Tab text on tabbed MDI tabs will now trim long text with ellipses in the middle, instead of the end, allowing for filenames to be more readable.

SyntaxEditor's completion and parameter info providers in all language add-ons now allow you to intercept OnSessionOpening, even when no items were pre-populated, so that you can add your own custom items/info.  Cut, copy, paste, drag, and drop all now support the block and full line flags that are compatible with Visual Studio.  The Python Language Add-on added a text range property to all type and function definitions, allowing you to implement features like go to definition easier.

The Shared Library added a new RingSpinner control that is an animated ring where the two ring segment ends chase each other around the circle.  It's great for display while performing a lengthy operation.

All products received numerous other minor enhancements and bug fixes.  See the announcement posts for the detailed list of enhancements and updates:

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