Infragistics(R) NetAdvantage(R) Windows Forms
Locations Property
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Infragistics.Win.Misc Namespace > UltraNavigationBarLocation Class : Locations Property

Returns the NavigationBarLocationsCollection instance which contains this UltraNavigationBarLocation instance's immediate children.

Syntax

Visual Basic (Declaration) 
Public ReadOnly Property Locations As NavigationBarLocationsCollection
C# 
public NavigationBarLocationsCollection Locations {get;}

Example

The following code sample demonstrates how to populate an UltraNavigationBar control and an UltraTree control with the contents of the local machine's file system:

Visual BasicCopy Code
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

    Public Sub Populate()

        '  Set up the root location to represent the 'Computer' location.
        Dim rootLocation As UltraNavigationBarLocation = Me.navigationBar.RootLocation

        '  Remove any existing members from the root's Locations collection.
        If (rootLocation.HasLocations) Then rootLocation.Locations.Clear()

        '  Clear the tree's Nodes collection and add the root node.
        Me.tree.Nodes.Clear()
        Dim rootNode As UltraTreeNode = Me.tree.Nodes.Add("Computer", "Computer")

        '  Set the Text for the root location and root node
        rootLocation.Text = rootNode.Text

        '  Note that we set the IncludeTextInFullPath property to false
        '  so that directory paths can be parsed without the end user
        '  having to type the name of the root. This will also prevent
        '  the text from appearing when the control is in edit mode.
        rootLocation.IncludeTextInFullPath = False

        '  Add the logical drives of this local machine to the root's Locations/Nodes collections.
        Dim locations As NavigationBarLocationsCollection = rootLocation.Locations
        Dim nodes As TreeNodesCollection = rootNode.Nodes

        '  Assign the appropriate image to the root location/node
        rootLocation.Settings.Appearance.Image = Me.GetImage(Images.Computer)
        rootNode.Override.NodeAppearance.Image = Me.GetImage(Images.Computer)

        Dim drives() As DriveInfo = DriveInfo.GetDrives()
        Dim i As Integer
        For i = 0 To drives.Length - 1

            Dim drive As DriveInfo = drives(i)

            '  Skip the drives we don't want to present to the end user.
            If (drive.DriveType = DriveType.Ram Or drive.DriveType = DriveType.NoRootDirectory Or drive.IsReady = False) Then
                Continue For
            End If

            '  Get the name of the drive, and remove the path separator.
            '  Also, get the volume name and use 'Local Disk' if none is assigned.
            Dim driveName As String = drive.Name
            driveName = driveName.Replace(PATH_SEPARATOR, String.Empty)
            Dim volumeLabel As String = drive.VolumeLabel
            volumeLabel = iif(Not volumeLabel Is Nothing AndAlso volumeLabel.Length > 0, volumeLabel, "Local Disk")

            '  Create a new UltraNavigationBarLocation instance, using the drive's name
            '  as the key, and the volume label/drive name as the DisplayText.
            Dim location As UltraNavigationBarLocation = New UltraNavigationBarLocation(driveName, driveName)

            '  Use the DisplayText property to format the combination of the drive letter
            '  and volume name so that we present it to the end user in a readable form.
            location.DisplayText = String.Format("{0} ({1})", volumeLabel, driveName)

            '  Add the location to the root's Locations collection.
            locations.Add(location)

            '  Add an accompanying tree node for the location we just added
            Dim node As UltraTreeNode = rootNode.Nodes.Add(location.Key, location.DisplayTextResolved)

            '  Assign the appropriate image to the location/node
            location.Settings.Appearance.Image = Me.GetImage(drive.DriveType)
            node.Override.NodeAppearance.Image = Me.GetImage(drive.DriveType)

            '  Assign an instance of a wrapper class which associates the node,
            '  location and directory to each object to the Tag property.
            node.Tag = New DirectoryWrapper(drive.RootDirectory, location)
            location.Tag = New DirectoryWrapper(drive.RootDirectory, node)
        Next

    End Sub

	End Class
C#Copy Code
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 static readonly string PATH_SEPARATOR = "\\";
        private UltraNavigationBar navigationBar = null;
        private UltraTree tree = null;

        public void Populate()
        {
            try
            {
                System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor;

                //  Set up the root location to represent the 'Computer' location.
                UltraNavigationBarLocation rootLocation = this.navigationBar.RootLocation;
                
                //  Remove any existing members from the root's Locations collection.
                if ( rootLocation.HasLocations )
                    rootLocation.Locations.Clear();

                //  Clear the tree's Nodes collection and add the root node.
                this.tree.Nodes.Clear();
                UltraTreeNode rootNode = this.tree.Nodes.Add( "Computer", "Computer" );

                //  Set the Text for the root location and root node
                rootLocation.Text = rootNode.Text;

                //  Note that we set the IncludeTextInFullPath property to false
                //  so that directory paths can be parsed without the end user
                //  having to type the name of the root. This will also prevent
                //  the text from appearing when the control is in edit mode.
                rootLocation.IncludeTextInFullPath = false;
                
                //  Add the logical drives of this local machine to the root's Locations/Nodes collections.
                NavigationBarLocationsCollection locations = rootLocation.Locations;
                TreeNodesCollection nodes = rootNode.Nodes;

                //  Assign the appropriate image to the root location/node
                rootLocation.Settings.Appearance.Image = this.GetImage(Images.Computer);
                rootNode.Override.NodeAppearance.Image = this.GetImage(Images.Computer);

                DriveInfo[] drives = DriveInfo.GetDrives();
                for ( int i = 0; i < drives.Length; i ++ )
                {
                    DriveInfo drive = drives[i];
                    
                    //  Skip the drives we don't want to present to the end user.
                    if ( drive.DriveType == DriveType.Ram ||
                         drive.DriveType == DriveType.NoRootDirectory ||
                         drive.IsReady == false )
                        continue;

                    //  Get the name of the drive, and remove the path separator.
                    //  Also, get the volume name and use 'Local Disk' if none is assigned.
                    string driveName = drive.Name;
                    driveName = driveName.Replace( PATH_SEPARATOR, string.Empty );
                    string volumeLabel = drive.VolumeLabel;
                    volumeLabel = volumeLabel != null && volumeLabel.Length > 0 ? volumeLabel : "Local Disk";

                    //  Create a new UltraNavigationBarLocation instance, using the drive's name
                    //  as the key, and the volume label/drive name as the DisplayText.
                    UltraNavigationBarLocation location = new UltraNavigationBarLocation( driveName, driveName );

                    //  Use the DisplayText property to format the combination of the drive letter
                    //  and volume name so that we present it to the end user in a readable form.
                    location.DisplayText = string.Format("{0} ({1})", volumeLabel, driveName );

                    //  Add the location to the root's Locations collection.
                    locations.Add( location );

                    //  Add an accompanying tree node for the location we just added
                    UltraTreeNode node = rootNode.Nodes.Add( location.Key, location.DisplayTextResolved );

                    //  Assign the appropriate image to the location/node
                    location.Settings.Appearance.Image = this.GetImage(drive.DriveType);
                    node.Override.NodeAppearance.Image = this.GetImage(drive.DriveType);

                    //  Assign an instance of a wrapper class which associates the node,
                    //  location and directory to each object to the Tag property.
                    node.Tag = new DirectoryWrapper( drive.RootDirectory, location );
                    location.Tag = new DirectoryWrapper( drive.RootDirectory, node );
                }
            }
            finally
            {
                System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default;
            }
        }
    }

Remarks

The navigation path displayed by the UltraNavigationBar control is a recursive representation of Locations collections; each member of the navigation path is a member of its UltraNavigationBarLocation.Parent location's Locations collection. The RootLocation represents the origin of the navigation path; all members of all Locations collections associated with a given UltraNavigationBar instance are descendants of that UltraNavigationBar's RootLocation.

The Locations collection contains all children of the parent location, regardless of their visibility, and in the order in which they were added to the collection. The collection's NavigationBarLocationsCollection.VisibleMembers property returns a read-only collection which contains only the UltraNavigationBarLocation instances whose Visible property is set to true, in the order in which they appear in the user interface. This collection can be sorted using the NavigationBarLocationsCollection.VisibleLocationsCollection.Sort method to change the order in which locations appear in the user interface.

The UltraNavigationBar supports "lazy loading" of its Locations collection via the UltraNavigationBar.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.

See Also