'Declaration Public Event InitializeLocations As InitializeLocationsHandler
public event InitializeLocationsHandler InitializeLocations
The event handler receives an argument of type InitializeLocationsEventArgs containing data related to this event. The following InitializeLocationsEventArgs properties provide information specific to this event.
Property | Description |
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ParentLocation | Returns the Infragistics.Win.Misc.UltraNavigationBarLocation instance whose Infragistics.Win.Misc.UltraNavigationBarLocation.Locations collection is being initialized. |
The UltraNavigationBar supports "lazy loading" of its UltraNavigationBarLocation.Locations collections via the InitializeLocations event. When the collection's NavigationBarLocationsCollection.Count property, enumerator, or indexer is accessed for the first time, the event fires, giving listeners the opportunity to populate the collection in a manner that is transparent to the end user. This approach is useful in the case where populating all Locations collections would cause performance degradation; each individual collection is populated in an "on demand" fashion, deferring the usage of CPU time and other resources until the collection is actually requested. The collection can be reinitialized by calling its NavigationBarLocationsCollection.Reset method, specifying true as the value of the 'reInitialize' parameter.
Imports System Imports System.Drawing Imports System.IO Imports System.Collections.Generic Imports System.ComponentModel Imports Infragistics.Shared Imports Infragistics.Win Imports Infragistics.Win.Misc Imports Infragistics.Win.Misc.UltraWinNavigationBar Imports Infragistics.Win.UltraWinTree Public Class FileSystemSupport Private Const PATH_SEPARATOR As String = "\" Private navigationBar As UltraNavigationBar = Nothing Private tree As UltraTree = Nothing Private Sub Populate(ByVal directory As DirectoryInfo, ByVal location As UltraNavigationBarLocation) Dim childDirectories As DirectoryInfo() Try childDirectories = directory.GetDirectories() Catch Return End Try Try System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor If (childDirectories Is Nothing Or childDirectories.Length = 0) Then Return ' Get a reference to the collection Dim locations As NavigationBarLocationsCollection = location.Locations Dim wrapper As DirectoryWrapper = Nothing If Not location.Tag Is Nothing Then wrapper = location.Tag Dim parentNode As UltraTreeNode = wrapper.AssociatedObject Dim nodes As TreeNodesCollection = parentNode.Nodes ' Clear each collections if it is not empty If (locations.Count > 0) Then locations.Clear() If (nodes.Count > 0) Then nodes.Clear() Dim i As Integer For i = 0 To childDirectories.Length - 1 ' Get the DirectoryInfo object for this child directory Dim childDirectory As DirectoryInfo = childDirectories(i) ' If the directory is hidden, don't add a location for it. If ((childDirectory.Attributes And FileAttributes.Hidden) = FileAttributes.Hidden) Then Continue For ' Create an UltraNavigationBarLocation instance for the child directory ' also create the associated UltraTreeNode so we can attach it to the location. Dim childLocation As UltraNavigationBarLocation = New UltraNavigationBarLocation(childDirectory.FullName, childDirectory.Name) Dim childNode As UltraTreeNode = New UltraTreeNode(childLocation.Key, childLocation.Text) ' Assign an instance of a wrapper class which associates the node ' and directory to this location to its Tag property. childLocation.Tag = New DirectoryWrapper(childDirectory, childNode) ' Assign an instance of a wrapper class which associates the location ' and directory to this node to its Tag property. childNode.Tag = New DirectoryWrapper(childDirectory, childLocation) ' Add the UltraNavigationBarLocation which represents this directory ' to the Locations collection of the specified location. locations.Add(childLocation) ' Add the child node to the parent's Nodes collection nodes.Add(childNode) Next Finally System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default End Try End Sub ' Handles the UltraNavigationBar's 'InitializeLocations' event. Private Sub OnNavigationBarInitializeLocations(ByVal sender As Object, ByVal e As InitializeLocationsEventArgs) ' Populate the collection with the contents of the parent directory Dim parentLocation As UltraNavigationBarLocation = e.ParentLocation Dim wrapper As DirectoryWrapper = Nothing If Not parentLocation.Tag Is Nothing Then wrapper = parentLocation.Tag If (wrapper Is Nothing) Then Return Dim directoryInfo As DirectoryInfo = wrapper.DirectoryInfo Me.Populate(directoryInfo, parentLocation) End Sub ' Handles the UltraTree's 'BeforeExpand' event. Private Sub OnTreeBeforeExpand(ByVal sender As Object, ByVal e As CancelableNodeEventArgs) ' Acccess the associated UltraNavigationBarLocation's Locations collection; ' note that this will trigger the population of the Locations collection ' if necessary, which will in turn populate this node's Nodes collection. Dim parentNode As UltraTreeNode = e.TreeNode Dim wrapper As DirectoryWrapper = Nothing If Not parentNode.Tag Is Nothing Then wrapper = parentNode.Tag Dim location As UltraNavigationBarLocation = Nothing If Not wrapper Is Nothing Then location = wrapper.AssociatedObject Else location = Me.navigationBar.RootLocation Dim count As Integer = location.Locations.Count End Sub ' Handles the UltraNavigationBar's 'SelectedLocationChanged' event. Private Sub OnNavigationBarSelectedLocationChanged(ByVal sender As Object, ByVal e As SelectedLocationChangedEventArgs) ' Synchronize the UltraTree with the UltraNavigationBar by activating and selecting ' the node associated with the new SelectedLocation. Dim wrapper As DirectoryWrapper = Nothing If Not e.SelectedLocation.Tag Is Nothing Then wrapper = e.SelectedLocation.Tag Dim node As UltraTreeNode = Nothing If Not wrapper Is Nothing Then node = wrapper.AssociatedObject Else node = Me.tree.Nodes(0) Me.tree.ActiveNode = node node.Selected = True End Sub ' Handles the UltraTree's 'AfterActivate' event. Private Sub OnTreeAfterActivate(ByVal sender As Object, ByVal e As NodeEventArgs) ' Synchronize the UltraNavigationBar with the UltraTree by selecting ' the location associated with the new ActiveNode. Dim activeNode As UltraTreeNode = e.TreeNode Dim wrapper As DirectoryWrapper = Nothing wrapper = IIf(Not activeNode Is Nothing, activeNode.Tag, Nothing) Dim location As UltraNavigationBarLocation = Nothing If Not wrapper Is Nothing Then location = wrapper.AssociatedObject Else location = Me.navigationBar.RootLocation If (Not location Is Nothing) Then Me.navigationBar.SelectedLocation = location End Sub End Class
using System; using System.Drawing; using System.IO; using System.Collections.Generic; using System.ComponentModel; using Infragistics.Shared; using Infragistics.Win; using Infragistics.Win.Misc; using Infragistics.Win.Misc.UltraWinNavigationBar; using Infragistics.Win.UltraWinTree; public class FileSystemSupport { private const string PATH_SEPARATOR = "\\"; private UltraNavigationBar navigationBar = null; private UltraTree tree = null; private void Populate( DirectoryInfo directory, UltraNavigationBarLocation location ) { DirectoryInfo[] childDirectories = null; try { childDirectories = directory.GetDirectories(); } catch { return; } try { System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor; if ( childDirectories != null && childDirectories.Length > 0 ) { // Get a reference to the collection NavigationBarLocationsCollection locations = location.Locations; DirectoryWrapper wrapper = location.Tag as DirectoryWrapper; UltraTreeNode parentNode = wrapper.AssociatedObject as UltraTreeNode; TreeNodesCollection nodes = parentNode.Nodes; // Clear each collections if it is not empty if ( locations.Count > 0 ) locations.Clear(); if ( nodes.Count > 0 ) nodes.Clear(); for ( int i = 0; i < childDirectories.Length; i ++ ) { // Get the DirectoryInfo object for this child directory DirectoryInfo childDirectory = childDirectories[i]; // If the directory is hidden, don't add a location for it. if ( (childDirectory.Attributes & FileAttributes.Hidden) == FileAttributes.Hidden ) continue; // Create an UltraNavigationBarLocation instance for the child directory; // also create the associated UltraTreeNode so we can attach it to the location. UltraNavigationBarLocation childLocation = new UltraNavigationBarLocation( childDirectory.FullName, childDirectory.Name ); UltraTreeNode childNode = new UltraTreeNode( childLocation.Key, childLocation.Text ); // Assign an instance of a wrapper class which associates the node // and directory to this location to its Tag property. childLocation.Tag = new DirectoryWrapper( childDirectory, childNode ); // Assign an instance of a wrapper class which associates the location // and directory to this node to its Tag property. childNode.Tag = new DirectoryWrapper( childDirectory, childLocation ); // Add the UltraNavigationBarLocation which represents this directory // to the Locations collection of the specified location. locations.Add( childLocation ); // Add the child node to the parent's Nodes collection nodes.Add( childNode ); } } } finally { System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default; } } // Handles the UltraNavigationBar's 'InitializeLocations' event. private void OnNavigationBarInitializeLocations(object sender, InitializeLocationsEventArgs e) { // Populate the collection with the contents of the parent directory UltraNavigationBarLocation parentLocation = e.ParentLocation; DirectoryWrapper wrapper = parentLocation.Tag as DirectoryWrapper; if ( wrapper == null ) return; DirectoryInfo directoryInfo = wrapper.DirectoryInfo; this.Populate( directoryInfo, parentLocation ); } /// Handles the UltraTree's 'BeforeExpand' event. private void OnTreeBeforeExpand(object sender, CancelableNodeEventArgs e) { // Acccess the associated UltraNavigationBarLocation's Locations collection; // note that this will trigger the population of the Locations collection // if necessary, which will in turn populate this node's Nodes collection. UltraTreeNode parentNode = e.TreeNode; DirectoryWrapper wrapper = parentNode.Tag as DirectoryWrapper; UltraNavigationBarLocation location = wrapper != null ? wrapper.AssociatedObject as UltraNavigationBarLocation : this.navigationBar.RootLocation; int count = location.Locations.Count; } /// Handles the UltraNavigationBar's 'SelectedLocationChanged' event. private void OnNavigationBarSelectedLocationChanged(object sender, SelectedLocationChangedEventArgs e) { // Synchronize the UltraTree with the UltraNavigationBar by activating and selecting // the node associated with the new SelectedLocation. DirectoryWrapper wrapper = e.SelectedLocation.Tag as DirectoryWrapper; UltraTreeNode node = wrapper != null ? wrapper.AssociatedObject as UltraTreeNode : this.tree.Nodes[0]; this.tree.ActiveNode = node; node.Selected = true; } /// Handles the UltraTree's 'AfterActivate' event. private void OnTreeAfterActivate(object sender, NodeEventArgs e) { // Synchronize the UltraNavigationBar with the UltraTree by selecting // the location associated with the new ActiveNode. UltraTreeNode activeNode = e.TreeNode; DirectoryWrapper wrapper = activeNode != null ? activeNode.Tag as DirectoryWrapper : null; UltraNavigationBarLocation location = wrapper != null ? wrapper.AssociatedObject as UltraNavigationBarLocation : null; if ( location != null ) this.navigationBar.SelectedLocation = location; } }
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2