The ASPxTreeList fully exploits existing DevExpress appearance and data management technologies for ASP.NET. Features such as on-demand loading of individual nodes and callback support ensure that the solutions you build are both elegant and effective. In our implementation, the control never needs to transmit the entire tree structure when being updated. The ASPxTreeList is smart enough to determine which portion of the tree to be renewed and only requests a few records from the server, making user interaction lightning fast.

ASPxTreeList - Access and Manipulate Data

Four Data Access Options

To ensure that your data can be easily displayed within the ASPxTreeList, we provide the following data binding options:

• Unbound Mode
  You can build the desired tree structure in code using specially designed methods.
• Dinamic Node Loading
  At your option, you can populate only root-level nodes within the tree. Attempts to expand parent nodes with children will raise an event wherein you can specify the child nodes to be displayed. This approach offers significant performance gains against large datasets.
• Bind to a Hierarchical Data Source
  If you bind to a hierarchical data source, such as a site map, the control will automatically build the corresponding tree.
• Bind to a Standard Data Source
  When binding to a standard data source, you need to have two service fields to build a tree. One should specify a record's unique ID and the other should specify the parent record's ID.

Data Sorting

To make it easier to locate records within the control, the ASPxTreeList allows you to sort nodes against an unlimited number of columns.

As you might expect, end-users can easily initiate sort operations by simply clicking column headers.

Data Summaries

If your web application requires data analysis, the data summary feature of the ASPxTreeList allows you to focus on the overall numbers instead of having to deal with individual records. You can either summarize data across all records or only those records with a common parent. In both instances, five built-in functions are at your service or you can manually summarize values using a specially designed event. The aggregate result is displayed within the control's footer or group footer. And note that you aren't limited to a single summary per column - you can calculate as many summaries as needed.

Conditional Formatting

To highlight important data or better indicate differences between values, you can use Conditional Formatting. With this feature, entire records or individual cells can be formatted depending upon the data they contain.

The simplest use scenario is to highlight records or cells that have a particular value or that have values above or below a particular limit. Beyond these, you can also apply a "color map". This means that cells will use shades of the same color - lighter shades for smaller numbers and darker shades for higher numbers.

ASPxTreeList - Layout and Navigation Features

The following are just a few of the navigation and layout customization features available to you within the ASPxTreeList.

Focused and Selected Rows

You can enable the focused row feature to indicate the last clicked tree node. This is useful when using the Treeview for navigation purposes...indicating the end-user's current position. It can also be used with data-browser trees when you must display node details in a separate control. For instance, it can be used when displaying forum messages...highlighting the node whose details are currently displayed.

Multi-node selection is also a built-in feature of the ASPxTreeList. By toggling a single option, you can enable selection checkboxes within rows and display a Select All check box within the header panel.

Data Paging

If your tree contains many records, you can split data across multiple pages and thus guarantee a more efficient use of page space and faster initial page rendering. If you do so, the ASPxTreeList displays a built-in ASPxPager control allowing you to navigate to the required page via AJAX callbacks.

Customization Window (Field Chooser)

If end-users need to temporarily hide columns or make hidden columns visible, you can enable a Microsoft Outlook style Field Chooser window. End-users can simply drag fields to the window to hide them and then drag them back to the column header panel to make them visible again.

Node Preview Sections

To elegantly display memo fields, you can use the ASPxTreeList's built-in node preview feature. For instance, if you use the control to create a web forum, this feature allows you to preview individual messages within a discussion thread.