通过转换器绑定到ObservableCollection的文本字符串在集合更改时不更新

public class MyViewModel : INotifyPropertyChanged
{
    private ObservableCollection<string> _myCollection;
    public ObservableCollection<string> MyCollection
    {
        get { return _myCollection; }
        set
        {
            _myCollection = value;
            OnPropertyChanged(nameof(MyCollection));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class CollectionToStringConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value is ObservableCollection<string> collection)
        {
            return string.Join(", ", collection);
        }
        return string.Empty;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

<Window.Resources>
    <local:CollectionToStringConverter x:Key="CollectionToStringConverter" />
</Window.Resources>

<Grid>
    <TextBlock Text="{Binding MyCollection, Converter={StaticResource CollectionToStringConverter}}" />
</Grid>