Remember and navigate through multiple sets of state for a single page instance
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="CustomContentStateNavigationSample.StateNavigationPage"
xmlns:ns="clr-namespace:CustomContentStateNavigationSample">
<DockPanel>
<DockPanel.Resources>
<ObjectDataProvider x:Key="usersDataSource" ObjectType="{x:Type ns:Users}"/>
<DataTemplate x:Key="NameTemplate">
<TextBlock Text="{Binding Path=Name}"/>
</DataTemplate>
</DockPanel.Resources>
<Button Name="removeBackEntryButton" DockPanel.Dock="Top" Click="removeBackEntryButton_Click" Height="25">Remove Back Entry</Button>
<ListBox Name="userListBox" DockPanel.Dock="Top" Height="150" SelectionChanged="userListBox_SelectionChanged" DataContext="{StaticResource usersDataSource}" ItemsSource="{Binding}" IsSynchronizedWithCurrentItem="True" ItemTemplate="{StaticResource NameTemplate}" />
<ListBox Name="logListBox" ScrollViewer.CanContentScroll="True" ScrollViewer.HorizontalScrollBarVisibility="Visible" ScrollViewer.VerticalScrollBarVisibility="Visible"></ListBox>
</DockPanel>
</Page>
//File:Window.xaml.vb
Imports System
Imports System.Collections.ObjectModel
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Navigation
Imports System.Collections.Generic
Imports System.Text
Namespace CustomContentStateNavigationSample
Public Partial Class StateNavigationPage
Inherits Page
Implements IProvideCustomContentState
Private Sub removeBackEntryButton_Click(sender As Object, e As RoutedEventArgs)
If Me.NavigationService.CanGoBack Then
Dim entry As JournalEntry = Me.NavigationService.RemoveBackEntry()
Dim state As UserCustomContentState = DirectCast(entry.CustomContentState, UserCustomContentState)
Me.logListBox.Items.Insert(0, "RemoveBackEntry: " & state.JournalEntryName)
End If
End Sub
Friend Sub userListBox_SelectionChanged(sender As Object, e As SelectionChangedEventArgs)
If e.RemovedItems.Count = 0 Then
Return
End If
Dim previousUser As User = TryCast(e.RemovedItems(0), User)
Me.logListBox.Items.Insert(0, "AddBackEntry: " & previousUser.Name)
Dim userPageState As New UserCustomContentState(previousUser)
Me.NavigationService.AddBackEntry(userPageState)
End Sub
Private Function IProvideCustomContentState_GetContentState() As CustomContentState Implements IProvideCustomContentState.GetContentState
Dim currentUser As User = TryCast(Me.userListBox.SelectedItem, User)
Me.logListBox.Items.Insert(0, "GetContentState: " & currentUser.Name)
Return New UserCustomContentState(currentUser)
End Function
End Class
Public Class User
Private m_name As String
Public Sub New()
End Sub
Public Sub New(name As String)
Me.m_name = name
End Sub
Public Property Name() As String
Get
Return m_name
End Get
Set
m_name = value
End Set
End Property
End Class
<Serializable> _
Class UserCustomContentState
Inherits CustomContentState
Private user As User
Public Sub New(user As User)
Me.user = user
End Sub
Public Overrides ReadOnly Property JournalEntryName() As String
Get
Return Me.user.Name
End Get
End Property
Public Overrides Sub Replay(navigationService As NavigationService, mode As NavigationMode)
Dim page As StateNavigationPage = DirectCast(navigationService.Content, StateNavigationPage)
Dim userListBox As ListBox = page.userListBox
RemoveHandler page.userListBox.SelectionChanged, AddressOf page.userListBox_SelectionChanged
page.userListBox.SelectedItem = Me.user
AddHandler page.userListBox.SelectionChanged, AddressOf page.userListBox_SelectionChanged
End Sub
End Class
Public Class Users
Inherits ObservableCollection(Of User)
Public Sub New()
Me.Add(New User("A"))
Me.Add(New User("B"))
Me.Add(New User("C"))
Me.Add(New User("D"))
Me.Add(New User("E"))
Me.Add(New User("F"))
Me.Add(New User("G"))
End Sub
End Class
End Namespace
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