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INotifyPropertyChanged Not Working, I need some guide

I made an application with Windows template studio, As MVVM,
The Problem exists in ShellPage which contains some Controls, 2 Image , TextBlock, the NavigationView, and of course the Frame that holds all other pages.
The code here is for the TextBlock, but the Problem same for the 2 Image controls also.
in ShellPage.xaml:
xmlns:myControls="using:Numbers_to_Text.MyControls"
d:DataContext="{d:DesignInstance Type=viewmodels:ShellViewModel}"
Height="650" Width="1000" MaxHeight="650" MaxWidth="1000" MinHeight="650" MinWidth="1000"
mc:Ignorable="d" Background="{x:Null}">
<Page.Resources>
<helpers:AppSettings x:Key="AppSettings" />
</Page.Resources>
<TextBlock x:FieldModifier="public" x:Name="PageTitle" Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="1"
Canvas.ZIndex="2" TextAlignment="DetectFromContent" HorizontalTextAlignment="DetectFromContent"
VerticalAlignment="Bottom" FontWeight="Bold" Text="{Binding ChangeTitle, Mode=TwoWay}"/>
in ShellPage.xaml.cs:
public ShellPage()
{
InitializeComponent();
DataContext = ViewModel;
ViewModel.Initialize(shellFrame, navigationView, KeyboardAccelerators);
}
and in ShellViewModel.cs
private void OnItemInvoked(WinUI.NavigationViewItemInvokedEventArgs args)
{
if (args.IsSettingsInvoked)
{
NavigationService.Navigate(typeof(SettingsPage), null, args.RecommendedNavigationTransitionInfo);
ChangeTitle = "Settings";
}
else
{
var selectedItem = args.InvokedItemContainer as WinUI.NavigationViewItem;
var pageType = selectedItem?.GetValue(NavHelper.NavigateToProperty) as Type;
if (pageType != null)
{
NavigationService.Navigate(pageType, null, args.RecommendedNavigationTransitionInfo);
ChangeTitle= pageType.Name;
}
}
}
private string _changeTitle;
public string ChangeTitle
{
get { return _changeTitle= GetTitle(); }
set
{
_changeTitle = value;
RaisePropertyChanged(nameof(ChangeTitle));
}
}
private static string GetTitle()
{
try
{
var resourceLoader = Windows.ApplicationModel.Resources.ResourceLoader.GetForCurrentView();
return NavigationService.Frame.Content != null
? resourceLoader.GetString(NavigationService.Frame.Content.GetType().Name)
: "Error Page Title";
}
catch
{
return "Welcome to Main Page";
}
}
public event PropertyChangedEventHandler propertyChanged;
public void NotifyPropertyChanged([CallerMemberName] string propName = "")
{
propertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));
}
public void RaisePropertyChanged([CallerMemberName] string propertyName = "")
{
this.propertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
Why ChangeTitle not changing when navigation occured?
I used breakPoints to trace the ChangeTitle, I implemented PropertyChangedEventHandler inside the shellViewModel instead to make sure that the property setter is call the NotifyPropertyChanged, with no luck.

Revit API WPF C#: Check All button for Check Boxes in Listbox

I'm pretty new to programming with WPF and C# and I have a question regarding the possibility to automatically check all the CheckBoxes in a Listbox. I'm developing a plugin for Autodesk Revit and, after having listed all the names of the rooms in a list box, I want to check them all using the button "Check All"
I've read the thread at this page but still, I'm not able to make it work. May someone help me with my code?
Here is what I've done:
XAML:
<ListBox x:Name='roomlist'
SelectionMode='Multiple'>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox IsChecked='{Binding IsChecked}'
Content="{Binding}" />
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.InputBindings>
<KeyBinding Command="ApplicationCommands.SelectAll"
Modifiers="Ctrl"
Key="A" />
</ListBox.InputBindings>
<ListBox.CommandBindings>
<CommandBinding Command="ApplicationCommands.SelectAll" />
</ListBox.CommandBindings>
</ListBox>
C#
public partial class RoomsDistance_Form : Window
{
UIDocument _uidoc;
Document _doc;
public RoomsDistance_Form(Document doc, UIDocument uidoc)
{
InitializeComponent();
FilteredElementCollector collector = new FilteredElementCollector(doc)
.WhereElementIsNotElementType()
.OfCategory(BuiltInCategory.OST_Rooms);
List<String> myRooms = new List<String>();
foreach (var c in collector)
{
myRooms.Add(c.Name);
}
myRooms.Sort();
roomlist.ItemsSource = myRooms;
}
private void checkAllBtn_Click(object sender, RoutedEventArgs e)
{
foreach (CheckBox item in roomlist.Items.OfType<CheckBox>())
{
item.IsChecked = true;
}
}
public class Authority : INotifyPropertyChanged
{
private bool isChecked;
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
NotifyPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
Thank you very much for your help!

In the thread you are linking to, they are setting the "IsChecked" on the data object (Authority), not the CheckBox control itself.
foreach (var a in authorityList)
{
a.IsChecked = true;
}
You have a binding to IsChecked that will update the Checkbox control when NotifyPropertyChanged() is called.

After having lost my mind in the effort i solved my problem by avoiding the Listbox.. I simply added single CheckBoxes in the StackPanel.
XAML:
<ScrollViewer Margin='10,45,10,100'
BorderThickness='1'>
<StackPanel x:Name='stack'
Grid.Column='0'></StackPanel>
</ScrollViewer>
C#:
foreach (var x in myRooms)
{
CheckBox chk = new CheckBox();
chk.Content = x;
stack.Children.Add(chk);
}
Not what i was looking for but now it works and that's the point.
Thank you for your help!

I usually use CheckBoxList in the following way:
In xaml:
<ListBox ItemsSource="{Binding ListBoxItems, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"> //+some dimensional properties
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Name}" IsChecked="{Binding IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
In xaml.cs:
public partial class MyWindow : Window
{
public ViewModel ViewModel {get; set; }
public MyWindow(ViewModel viewModel)
{
//keep all the mess in ViewModel, this way your xaml.cs will not end up with 1k lines
ViewModel = viewModel;
DataContext = ViewModel;
InitializeComponent();
}
void BtnClick_SelectAll(object sender, RoutedEventArgs e)
{
ViewModel.CheckAll();
}
}
ViewModel preparation:
public class ViewModel
{
public List<ListBoxItem> ListBoxItems { get; set; }
//InitializeViewModel()...
//UpdateViewModel()...
//other things....
public void CheckAll()
{
foreach (var item in ListBoxItems)
{
item.IsSelected = true;
}
}
public class ListBoxItem : INotifyPropertyChanged
{
public string Name { get; set; }
private bool _isSelected;
public bool IsSelected
{
get { return _isSelected; }
set
{
if (_isSelected != value)
{
_isSelected = value;
OnPropertyChanged(nameof(IsSelected));
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}

ObservableCollection binding to listbox ui doesn't update

I know I should use the MVVM pattern but I'm trying to get step by step closer to it. So here is my Listbox:
<ListBox x:Name="BoardList" ItemsSource="{Binding notes}" >
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
<TextBox IsReadOnly="True" ScrollViewer.VerticalScrollBarVisibility="Visible" Text="{Binding text}" TextWrapping="Wrap" Foreground="DarkBlue"></TextBox>
<AppBarButton Visibility="{Binding visibility}" Icon="Globe" Click="OpenInBrowser" x:Name="Link"></AppBarButton>
<AppBarButton Icon="Copy" Click="Copy"></AppBarButton>
<AppBarButton Icon="Delete" Click="Delete"></AppBarButton>
</StackPanel>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
In the Mainpage.xaml.cs I declare the following:
ObservableCollection<BoardNote> notes = new ObservableCollection<BoardNote>();
So if I understood this right I don't need to care about the "INotifyCollectionChanged" stuff because I'm using an observablecollection?
So I got for example a textbox like this:
<Textbox x:Name="UserInputNote" Placeholdertext="Type in a text for your note"></Textbox>
And a button to Add the new note to the ObservableCollection and the click event is just like this:
notes.Add(new BoardNote(UserInputNote.Text));
So now the UI should update every time the user clicks the button to save a new note. But nothing happens. What did I do wrong?
If you need it here is the BoardNote class:
class BoardNote
{
public string text
{
get; set;
}
public BoardNote(string text)
{
this.text = text;
}
public Visibility visibility
{
get
{
if (text.StartsWith("http"))
return Visibility.Visible;
else
return Visibility.Collapsed;
}
}
}

You need to implement INotifyPropertyChanged. Here's one way of doing it.
Create this NotificationObject class.
public class NotificationObject : INotifyPropertyChanged
{
protected void RaisePropertyChanged<T>(Expression<Func<T>> action)
{
var propertyName = GetPropertyName(action);
RaisePropertyChanged(propertyName);
}
private static string GetPropertyName<T>(Expression<Func<T>> action)
{
var expression = (MemberExpression)action.Body;
var propertyName = expression.Member.Name;
return propertyName;
}
private void RaisePropertyChanged(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
public event PropertyChangedEventHandler PropertyChanged;
}
Then your BoardNote class will inherit it this way:
class BoardNote : NotificationObject
{
private string _text
public string Text
{
get {return _text;}
set
{
if(_text == value) return;
_text = value;
RaisePropertyChanged(() => Text);
}
}
public BoardNote(string text)
{
this.text = text;
}
public Visibility visibility
{
get
{
if (text.StartsWith("http"))
return Visibility.Visible;
else
return Visibility.Collapsed;
}
}
}

WPF, Property does not return value to the binding

So, I have a project with a scrolling text (marqee) that rotates over a string array. And I want it to change the string value after 20 seconds of each animation iteration.
There is a problem though, the property(ScrollingText) that uses the INotifyPropertyChanged interface to bind to a textblock(using XAML) does not return after the first iteration. Even though it refreshes normally(in the set part), it does not return on the Getter part.... except for the first set in the default ctor.
MAIN CLASS:
class GetScrollingText : CommonBase
{
private string _scrollingtext = String.Empty;
DoubleAnimation Animation;
public GetScrollingText()
{
ScrollingText = GetScrollString();
}
public string ScrollingText
{
get
{
return _scrollingtext;
}
set
{
if (value != _scrollingtext)
{
_scrollingtext = value;
RaisePropertyChanged("ScrollingText");
}
}
} // INJECTS the string in the animated textblock {binding}.
public TextBlock scrollBlock { get; set; }
string GetScrollString()
{
.........
return scrolltext;
}
public void LeftToRightMarqee(double from, double to)
{
Animation = new DoubleAnimation();
Animation.From = from;
Animation.To = to;
Animation.Duration = new Duration(TimeSpan.FromSeconds(20));
Animation.Completed += animation_Completed;
scrollBlock.BeginAnimation(Canvas.LeftProperty, Animation);
}
void animation_Completed(object sender, EventArgs e)
{
ScrollingText = GetScrollString();
scrollBlock.BeginAnimation(Canvas.LeftProperty, Animation);
}
}
For some reason the animation_Completed Event only changes the value ScrollingText, but it does not invoke the Getter part therefore there is not a return to the {binding}.
XAML:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:AnnouncingSys"
x:Class="AnnouncingSys.MainWindow"
x:Name="Window"
Width="1280" Height="720" MinHeight="566" MinWidth="710">
<Window.Resources>
<vm:GetScrollingText x:Key="ScrollingText"/>
</Window.Resources>
<Canvas x:Name="MainCanvas" ClipToBounds="True" Margin="0,0,0,0" Grid.Row="5" Background="Black" Grid.ColumnSpan="5" >
<TextBlock x:Name="ScrollBlock" TextWrapping="Wrap" VerticalAlignment="Top" Height="113" Width="5147" Canvas.Left="-1922" Text="{Binding ScrollingText, Source={StaticResource ScrollingText}}"/>
</Canvas>
</Window>
CODE BEHIND:
public partial class MainWindow : Window
{
GetScrollingText scrolling = new GetScrollingText();
public MainWindow()
{
InitializeComponent();
scrolling.scrollBlock = this.ScrollBlock;
scrolling.LeftToRightMarqee(2000, -3000);
}
}
And finally the helper class CommonBase:
public class CommonBase : INotifyPropertyChanged
{
protected CommonBase()
{
}
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChanged(string PropertyName)
{
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
PropertyChangedEventArgs e = new PropertyChangedEventArgs(PropertyName);
handler(this, e);
}
}
}
I have even put a breakpoint on the return block of the Getter but it only activates on the first: "ScrollingText = GetScrollString()". I mean, shouldn't it return each time the value is changed???

You are using two different instances of your GetScrollingText class, one in XAML as StaticResource, the other in code behind as the scrolling field in class MainWindow.
Instead of creating a StaticResource in XAML, you could just set the DataContext property of your MainWindow:
public partial class MainWindow : Window
{
GetScrollingText scrolling = new GetScrollingText();
public MainWindow()
{
InitializeComponent();
scrolling.scrollBlock = this.ScrollBlock;
scrolling.LeftToRightMarqee(2000, -3000);
DataContext = scrolling; // here
}
}
Now you would not explicitly set the binding's Source property, because the DataContext is used as default binding source:
<TextBlock ... Text="{Binding ScrollingText}"/>

Either adressing a property in a sub class or a binding issue

I have a problem and I'm not sure what it is. I have a class within a class that has a value that needs to be bound to a control, in this case visibility. The code is changing the value correctly but the output does not change (i.e collapse the control)
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel Orientation="Vertical">
<Button x:Name="buttonOne" Content="Show Hide" Width="Auto" Click="buttonOne_Click"/>
<ListBox x:Name="aListBox">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<TextBlock x:Name="blockOne" Grid.Column="0" Text="Raw "/>
<TextBlock x:Name="blockTwo" Grid.Column="1" Text="{Binding aValue}" Visibility="{Binding Path=visControl.VisibleState, BindsDirectlyToSource=True}"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</Grid>
public partial class MainPage : PhoneApplicationPage
{
private List<myClass> listOfClasses = new List<myClass>();
// Constructor
public MainPage()
{
myClass classA = new myClass("one");
myClass classB = new myClass("two");
myClass classC = new myClass("three");
listOfClasses.Add(classA);
listOfClasses.Add(classB);
listOfClasses.Add(classC);
InitializeComponent();
aListBox.ItemsSource = listOfClasses;
}
private void buttonOne_Click(object sender, RoutedEventArgs e)
{
foreach (myClass cl in listOfClasses)
if (cl.SwitchVisible)
cl.SwitchVisible = false;
else
cl.SwitchVisible = true;
}
}
public class myClass
{
private string _aValue;
private bool _switchVisible;
public bool SwitchVisible { get { return _switchVisible; } set { _switchVisible = value; visControl.changeVisibility(_switchVisible); } }
public string aValue { get { return _aValue; } }
public controlProperties visControl;
public myClass(string invalue)
{
visControl = new controlProperties();
visControl.VisibleState = Visibility.Visible;
_aValue = invalue;
}
}
public class controlProperties
{
private Visibility _visibility;
public Visibility VisibleState { get { return _visibility; } set { _visibility = value; } }
public void changeVisibility(bool isVisible)
{
if (isVisible)
_visibility = Visibility.Visible;
else
_visibility = Visibility.Collapsed;
}
}
Any ideas if this is a pathing issue or a binding problem?

If you want the control to be automatically updated when you change the value of the property, your class must implement the INotifyPropertyChanged interface.
For instance:
public class controlProperties : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private Visibility _visibility;
public Visibility VisibleState
{
get
{
return _visibility;
}
set
{
_visibility = value;
this.NotifyPropertyChanged("VisibleState");
}
}
public void changeVisibility(bool isVisible)
{
if (isVisible)
this.VisibleState = Visibility.Visible;
else
this.VisibleState = Visibility.Collapsed;
}
private void NotifyPropertyChanged(string propertyName)
{
var eventHandler = this.PropertyChanged;
if (eventHandler != null)
{
eventHandler(sender, new PropertyChangedEventArgs(propertyName));
}
}
}