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)
The TreeViewEventArgs type exposes the following members.
| 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 a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
For more information about handling events, see Consuming 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 ref class CustomizedTreeView: public TreeView { public: CustomizedTreeView() { // 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; } protected: virtual void OnAfterSelect( TreeViewEventArgs^ e ) override { // 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 ) { if ( e->Node->IsExpanded ) { e->Node->Collapse(); } else { e->Node->Expand(); } } // Remove the selection. This allows the same node to be // clicked twice in succession to toggle the expansion state. SelectedNode = nullptr; } };
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
