Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
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 'New 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
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.