TreeViewEventArgs Class
Provides data for the AfterCheck, AfterCollapse, AfterExpand, or AfterSelect events of a TreeView control.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
| Name | Description | |
|---|---|---|
![]() | TreeViewEventArgs(TreeNode) | Initializes a new instance of the TreeViewEventArgs class for the specified tree node. |
![]() | TreeViewEventArgs(TreeNode, TreeViewAction) | Initializes a new instance of the TreeViewEventArgs class for the specified tree node and with the specified type of action that raised the event. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Finalize() | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.) |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | MemberwiseClone() | |
![]() | ToString() | Returns a string that represents the current object.(Inherited from Object.) |
For more information about handling events, see Handling and Raising Events.
The following example illustrates a customized TreeView. By inheriting the TreeView class, this custom version has all the functionality of a normal TreeView. Changing various property values in the constructor provides a unique appearance. Because the ShowPlusMinus property is set to false, the customized control also overrides the OnAfterSelect method so nodes can be expanded and collapsed when they are clicked.
A control that is customized in this way can be used throughout an organization, making it easy to provide a consistent interface without requiring the control properties to be specified in each individual project.
Public Class CustomizedTreeView Inherits TreeView Public Sub New() ' Customize the TreeView control by setting various properties. BackColor = System.Drawing.Color.CadetBlue FullRowSelect = True HotTracking = True Indent = 34 ShowPlusMinus = False ' The ShowLines property must be false for the FullRowSelect ' property to work. ShowLines = False End Sub 'NewNew Protected Overrides Sub OnAfterSelect(ByVal e As TreeViewEventArgs) ' Confirm that the user initiated the selection. ' This prevents the first node from expanding when it is ' automatically selected during the initialization of ' the TreeView control. If e.Action <> TreeViewAction.Unknown Then If e.Node.IsExpanded Then e.Node.Collapse() Else e.Node.Expand() End If End If ' Remove the selection. This allows the same node to be ' clicked twice in succession to toggle the expansion state. SelectedNode = Nothing End Sub 'OnAfterSelect End Class 'CustomizedTreeView
Available since 1.1
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.


