NavigationTree Control

• Download demo project - 19.6 Kb
• Download source - 29.1 Kb

Introduction

This control provides a new kind of navigation for your applications. It uses the TreeNodes of a TreeView to offer functionality to the user.

Background

I saw this control in a commercial application, and I liked the look and feel and the possibilities it gives to the programmer. Because I didn't see such a control anywhere else, I decided to develop one on my own and use it in one of my projects. I hope others like my NavigationTree, too.

Using the code

When using a NavigationTree, you have to define categories and items. Categories are represented by NavigationCategory objects, and items are represented by NavigationItem objects. Each item is owned by a category, and the categories are owned by the NavigationTree. Items can be organized hierarchically.

Use categories to represent different parts of your application (like 'Customers', 'Manufacturers', 'Stock', an so on), and items to represent topics within a category (like 'customer list', 'search customer', 'new customer'). When a category is selected, its items will be displayed and the category header will be set.

When an item is selected, an event will be fired and your app can react on this event (e.g., display the customer list). You can use ImageLists to assign icons to NavigationItems and NavigationCategorys.

At the moment, NavigationCategorys and NavigationItems can only be added by code at runtime:

NavigationCategory c1 = new NavigationCategory("Customers", 0);
c1.Name = "catCustomer";

NavigationItem i = new NavigationItem("Master Data", 0);
i.AddChild(new NavigationItem("Customer List", 1));
i.AddChild(new NavigationItem("Details", 2));

c1.AddItem(i);
c1.AddItem(new NavigationItem("Orders", 3));
c1.AddItem(new NavigationItem("Invoices", 4));

navigationTree1.AddCategory(c1);

Add delegates to be informed when a NavigationItem is going to be selected, a NavigationItem has been selected, or a NavigationCategory has been selected:

// NavigationCategory has been selected
navigationTree1.OnCategorySelected += new 
   CategorySelected(navigationTree1_OnCategorySelected);

// NavigationItem is going to be selected
navigationTree1.OnBeforeItemSelect += new 
   BeforeItemSelect(navigationTree1_OnBeforeItemSelect);

// NavigationItem has been selected
navigationTree1.OnItemSelected += new 
   ItemSelected(navigationTree1_OnItemSelected);

You can select NavigationItems by code:

// select a NavigationItem and fire
// BeforeItemSelect and ItemSelected events
myNavItem.Select();
// select a NavigationItem without fireing events (silent mode)
myNavItem.Select(false);

You can change the Text property of a NavigationItems by code:

// change the visible text of a NavigationItem...
myNavItem.Text = "a new text";
// ...and update this NavigationItem in the NavigationTree
myNavItem.Refresh();

Points of Interest

I improved the NavigationTree step by step, as more functionality was needed in my project, so some parts of the source look rather wild and are not well documented. I'm going to improve the source when posting future versions. Suggestions, improvements, and bug reports are welcome.

History

• 3/28/06 - version 1.0 and demo project posted on CodeProject.