❔ WPF - Binding to last child of collection

I have the following setup:

public partial class StatusMessageService : ObservableObject
{
    [ObservableProperty] private ObservableCollection<string> _messageStack = new()
    {
        "Welcome to Rainbow Stone"
    };

    public string? LastMessage => MessageStack.LastOrDefault();

    public void AddMessage(string message)
    {
        MessageStack.Add(message);
    }
}

public partial class StatusMessageService : ObservableObject
{
    [ObservableProperty] private ObservableCollection<string> _messageStack = new()
    {
        "Welcome to Rainbow Stone"
    };

    public string? LastMessage => MessageStack.LastOrDefault();

    public void AddMessage(string message)
    {
        MessageStack.Add(message);
    }
}

I'm trying to output

LastMessage

LastMessage

in a StatusBar control.

I am following the solution 2 in: https://stackoverflow.com/a/38076864/2275217

However, the StatusBar does not update with new messages. A comment on SO says:

"In case of the property one would want to fire change notifications for said property in case of

CollectionChanged

CollectionChanged

."

However, this is not quite clear to me. What is meant by that? I am using CommunityToolkit.Mvvm for the Observable Object structure, but it wouldn't let me set

[ObservableProperty]

[ObservableProperty]

LastMessage

LastMessage

because it's a field.

How to update

LastMessage

LastMessage

along with the collection?

Stack Overflow

Binding to last array element

So far, i have an ObservableCollection<T> for objects.
I always want to display the last inserted element into a TextBlock. I implemented two solutions in XAML, but both not working:

<

❔ WPF - Binding to last child of collection

I have the following setup:

public partial class StatusMessageService : ObservableObject
{
    [ObservableProperty] private ObservableCollection<string> _messageStack = new()
    {
        "Welcome to Rainbow Stone"
    };

    public string? LastMessage => MessageStack.LastOrDefault();

    public void AddMessage(string message)
    {
        MessageStack.Add(message);
    }
}

public partial class StatusMessageService : ObservableObject
{
    [ObservableProperty] private ObservableCollection<string> _messageStack = new()
    {
        "Welcome to Rainbow Stone"
    };

    public string? LastMessage => MessageStack.LastOrDefault();

    public void AddMessage(string message)
    {
        MessageStack.Add(message);
    }
}

I'm trying to output

LastMessage

LastMessage

CollectionChanged

CollectionChanged

."

However, this is not quite clear to me. What is meant by that? I am using CommunityToolkit.Mvvm for the Observable Object structure, but it wouldn't let me set

[ObservableProperty]

[ObservableProperty]

LastMessage

LastMessage

because it's a field.

How to update

LastMessage

LastMessage

along with the collection?

Stack Overflow

Binding to last array element

So far, i have an ObservableCollection<T> for objects.
I always want to display the last inserted element into a TextBlock. I implemented two solutions in XAML, but both not working:

<

❔ WPF - Binding to last child of collection

❔ WPF - Binding to last child of collection

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