How to reset the source and keep the binding possible?

Question

In my solution I use specific class which contains a collection of some elements. When I want to Binding this collection I usually use a such path {Binding MyClass.InnerCollection}. It works fine before that moment when I will try to set another instance for that class, and than it's could not be binded.

Question: How to reset the source and keep the binding possible. Is it possible to reset the source without losing the binding without changing ItemsSource directly?

XAML

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <ListView ItemsSource="{Binding Container.InnerCollection}"/>

    <StackPanel Grid.Column="1">
        <Button Content="Add new item" Click="AddNewItem"/>
        <Button Content="Reset source" Click="ResetSource"/>
    </StackPanel>
</Grid>

C#

public partial class MainWindow : Window, INotifyPropertyChanged
{

    public MainWindow()
    {
        Container = new MyClass() { InnerCollection = new ObservableCollection<string>() { "Start" } };

        this.DataContext = this;
        InitializeComponent();
    }
    public MyClass Container { get; set; }

    public void AddNewItem(object sender, RoutedEventArgs e)
    {
        Container.InnerCollection.Add($"AddedItem");
    }
    public void ResetSource(object sender, RoutedEventArgs e)
    {
        Container = new MyClass() { InnerCollection = new ObservableCollection<string>() { $"Reseted" } };
    }
}

public class MyClass
{
    public ObservableCollection<string> InnerCollection { get; set; }
}

@RomanRyzhiy I know that if I reset only InnerCollection, everything will work fine. But time to time I reset this source (with Serialize and Deserialize) — Cobret, Nov 29 '22 at 12:23
`this.BindingContext = new MyClass() { InnerCollection = new ObservableCollection() { "Start" } };` — Roman Ryzhiy, Nov 29 '22 at 12:26
The Container property must fire the PropertyChanged event of the INotifyPropertyChanged interface. — Clemens, Nov 29 '22 at 12:54

score 0 · Answer 1 · answered Nov 29 '22 at 12:24

0

Let's reset only what you need to reset:

public void ResetSource(object sender, RoutedEventArgs e)
{
    Container.InnerCollection = new ObservableCollection<string>() { $"Reseted" };
}

answered Nov 29 '22 at 12:24

Roman Ryzhiy

1,540
8
5

This would require that MyClass also implements INotifyPropertyChanged and fires the PropertyChanged event when its InnerCollection property changes. – Clemens Nov 29 '22 at 12:55
@Clemens of course it does! I assume the ts knows what he/she is doing. – Roman Ryzhiy Nov 29 '22 at 13:18
That is perhaps a false assumption... – Clemens Nov 29 '22 at 13:21

How to reset the source and keep the binding possible?

1 Answers1