![]() ![]() You can use it in your applications if the original copyright is kept. The TreeViewAdv control is provided as free software with open source code. All that you need is to specify the name of the property of your class. The BindableControl class provides a ‘ DataPropertyName’ which is used in the control to read and write data to the node. This is the class diagram of all NodeControls provided by the library: Inherited classes should contain the code to draw the control and the code to respond on user actions – mouse and keyboard events. All controls must inherit from the ‘ NodeControl’ abstract class. In TreeViewAdv, you can use any number of NodeControl. The standard TreeView can display only one icon, CheckBox, and Label for each node. For each column, you can specify its header, width and alignment. UseColumns - Display data in columns or not.SelectionMode - Single (no multi-selection), Multi, MultiSameParent (children of only one node can be selected).LoadOnDemand - Read all child nodes at start-up or when the parent node expands.You should provide at least one NodeControl in order to see the model. ![]() NodeControls - The collection of controls which will be used to visualize the model.Model - Assign your model to this property to display it.There are a number of properties which help to customize the look and behavior of the TreeView. See the folder browser presented in the source code, for an example. If you need additional properties, you can create an ancestor of the Node class and use it in TreeModel.īut to use the full power of the TreeViewAdv, you should create your own realization of the ITreeModel interface. The Node class, which is used in TreeModel, contains only the ‘ Text’ and ‘ IsChecked’ properties. It stores the path from the root to the node, in the FullPath property. To specify the exact node in the model, TreePath class is used. For example, see the default implementation of the ITreeModel interface – the TreeModel class. The most common is the StructureChanged event, which cause the TreeView to fully refresh the specified node (or empty, for the whole model). If you wish TreeView to dynamically track model changes, you need to use one of several events of the ITreeModel interface. IsLeaf method tells TreeView whether it should try to read child nodes of the specified parent. GetChildren should return the list of child nodes of the specified parent (empty for root nodes). It’s very simple, and you need to implement only two methods. IEnumerable GetChildren(TreePath treePath) The model is described by ITreeModelInterface: The view asks the model for details, if needed, and displays the changes. If the model changes, it notifies the view by firing corresponding events. The main idea of this pattern is to split the model (business object) from its visualization (control). I really like the Model-View pattern, and decided to use it in this control. The following screenshots illustrate the TreeViewAdv features: NET code - No WinAPI is used in this control. Drag & Drop highlighting - Dynamically highlight the drop position.Load on Demand - Lazy load of child nodes.Multicolumns - You can split the TreeView into several columns.Unlimited number of controls for each node - You can display three icons + a CheckBox + two Labels.Multiselection - Maybe the first limitation which you will find in the standard TreeView is that it’s not possible to select more then one node.Model-View architecture - Will be covered in a separate section of this article. ![]() These are the key features of the TreeViewAdv control: The architecture of this control comes mainly from the Java Swing component, with some modifications. I could not find an alternative TreeView control which is free and fully meets my needs, so finally I decided to write my own. But learning this control to do something more complex is not an easy job. It works pretty well if you only need basic features. Of course, the first thing you will do is to use the standard. Working on several different projects, I was needed to display and edit hierarchical data. ![]()
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